What, if anything, is known about the practice of baptism for the dead in the early church?

Those whose aim is to air theological grievances on this topic will find this post unsatisfactory. Those looking for an analysis of early Christian texts may find it thought provoking .

The Shepherd of Hermas

The most thorough discussion of baptism for the dead in the early church comes from the Shepherd of Hermas (written either late 1st century or early 2nd century). In Similitude 9, he recounts the parable of the stones that were immersed in water before becoming part of the tower. The messenger provides the interpretation of the parable.

Key symbols to note:

• Stones = people
• Tower = kingdom of God
• Gate = the Son of God

First he notes that to be added to the tower one must receive the name of the Son of God:

4 Didst thou see," saith he, "that the stones which came through the gate have gone to the building of the tower, but those which came not through it were cast away again to their own place?" "I saw, Sir," say I. "Thus," saith he, "no one shall enter into the kingdom of God, except he receive the name of His Son.

5 For if thou wishest to enter into any city, and that city is walled all round and has one gate only, canst thou enter into that city except through the gate which it hath?" "Why, how, Sir," say I, "is it possible otherwise?" "If then thou canst not enter into the city except through the gate itself, even so," saith he, "a man cannot enter into the kingdom of God except by the name of His Son that is beloved by Him. (Sim. 9 12:4-5; note the echoes of John 3:5)

He subsequently teaches on the necessity of baptism and the preaching of the gospel to the dead:

2 "It was necessary for them," saith he, "to rise up through water, that they might be made alive; for otherwise they could not enter into the kingdom of God, except they had put aside the deadness of their [former] life.

3 So these likewise that had fallen asleep received the seal of the Son of God and entered into the kingdom of God. For before a man," saith he, "has borne the name of [the Son of] God, he is dead; but when he has received the seal, he layeth aside his deadness, and resumeth life.

4 The seal then is the water: so they go down into the water dead, and they come up alive. "thus to them also this seal was preached, and they availed themselves of it that they might enter into the kingdom of God."

5 "Wherefore, Sir," say I, "did the forty stones also come up with them from the deep, though they had already received the seal?" "Because," saith he, "these, the apostles and the teachers who preached the name of the Son of God, after they had fallen asleep in the power and faith of the Son of God, preached also to them that had fallen asleep before them, and themselves gave unto them the seal of the preaching.

6 Therefore they went down with them into the water, and came up again. But these went down alive [and again came up alive]; whereas the others that had fallen asleep before them went down dead and came up alive.

7 So by their means they were quickened into life, and came to the full knowledge of the name of the Son of God. For this cause also they came up with them, and were fitted with them into the building of the tower and were builded with them, without being shaped; for they fell asleep in righteousness and in great purity. Only they had not this seal. Thou hast then the interpretation of these things also." "I have, Sir," say I. (Sim. 9 15:2-7)

Some unpacking may be helpful. Verse 2 again echoes John 3:5, that being born of water is necessary to enter the kingdom of God, and verse 3 establishes that one bears/receives the name of the Son of God--which we saw in chapter 12 is necessary to enter the kingdom of God--through the seal.

The seal is described in verse 4 as going down into the water and coming up again in newness of life--echoing Paul's teaching on baptism.

Verse 5 explains that apostles and teachers (who had already been baptized), after death, proceeded to teach the gospel to those who were already dead and had not received baptism. In verse 7 it is acknowledged that among the dead were people who had lived a righteous life but had not received baptism. This seal of baptism was made available to not only the living but to the dead as well.

This sheds light on Paul's words in 1 Cor. 15:29, in which he acknowledges the existence of the practice of baptism for the dead, but says little about it. Paul does not condemn the practice; those interested in a hermeneutical discussion of the role this plays in Paul's argument may be interested in my post on this passage on the Hermeneutics site.

This belief that the dead who had never received the gospel would be taught by apostles & teachers (after their own deaths) is supported by multiple early Patristic writers.

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Clement of Alexandria

Clement believed that the gospel was taught in Hades by Jesus, and later the apostles. Clement shows particular concern for those who never had the opportunity in this life to learn the gospel truth.

Wherefore the Lord preached the Gospel to those in Hades. Accordingly the Scripture says, Hades says to Destruction, We have not seen His form, but we have heard His voice. It is not plainly the place, which, the words above say, heard the voice, but those who have been put in Hades, and have abandoned themselves to destruction, as persons who have thrown themselves voluntarily from a ship into the sea. They, then, are those that hear the divine power and voice. For who in his senses can suppose the souls of the righteous and those of sinners in the same condemnation, charging Providence with injustice?

But how? Do not [the Scriptures] show that the Lord preached the Gospel to those that perished in the flood, or rather had been chained, and to those kept in ward and guard? And it has been shown also, in the second book of the Stromata, that the apostles, following the Lord, preached the Gospel to those in Hades. For it was requisite, in my opinion, that as here, so also there, the best of the disciples should be imitators of the Master; so that He should bring to repentance those belonging to the Hebrews, and they the Gentiles; that is, those who had lived in righteousness according to the Law and Philosophy, who had ended life not perfectly, but sinfully. For it was suitable to the divine administration, that those possessed of greater worth in righteousness, and whose life had been pre-eminent, on repenting of their transgressions, though found in another place, yet being confessedly of the number of the people of God Almighty, should be saved, each one according to his individual knowledge.

...it is evident that those, too, who were outside of the Law, having lived rightly, in consequence of the peculiar nature of the voice, though they are in Hades and in ward, 1 Peter 3:19 on hearing the voice of the Lord, whether that of His own person or that acting through His apostles, with all speed turned and believed...So I think it is demonstrated that the God being good, and the Lord powerful, they save with a righteousness and equality which extend to all that turn to Him, whether here or elsewhere...

Did not the same dispensation obtain in Hades, so that even there, all the souls, on hearing the proclamation, might either exhibit repentance, or confess that their punishment was just, because they believed not? And it were the exercise of no ordinary arbitrariness, for those who had departed before the advent of the Lord (not having the Gospel preached to them, and having afforded no ground from themselves, in consequence of believing or not) to obtain either salvation or punishment. For it is not right that these should be condemned without trial, and that those alone who lived after the advent should have the advantage of the divine righteousness. (Stromata chapter 6)

Clement in fact quotes the Shepherd of Hermas approvingly on this point in the matter of the apostles taking the message & ordinances of the Gospel to the dead:

it is plain that, since God is no respecter of persons, the apostles also, as here, so there preached the Gospel to those of the heathen who were ready for conversion. And it is well said by the Shepherd, “They went down with them therefore into the water, and again ascended. But these descended alive, and again ascended alive. But those who had fallen asleep, descended dead, but ascended alive.” (ibid)

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Epiphanius

Writing in the late 4th century, Epiphanius explains that there was in the area around Corinth & Galatia, at one time a tradition of performing baptism on behalf of those who had died:

3 Again, he [Paul] likewise gives their refutation to those who say that Christ is not risen yet by saying, 'If Christ be not raised, our preaching is vain and our faith is vain. And we also are found false witnesses against God, because we testified against God that he raised up Christ, if so be that he raised him not up.' For in Corinth too certain persons arose to say there is no resurrection of the dead, as though it was apostolic preaching that Christ was not risen yet and the dead are not raised (at all).

4 For their school reached its height in this country, I mean Asia, and in Galatia as well. And in these countries I also heard of a tradition which said that when some of their people died too soon, without baptism, others would be baptized for them in their names, so that they would not be punished for rising unbaptized at the resurrection and become the subjects of the authority that made the world.

5 And the tradition I heard of says that this is why the same holy apostle said, 'If the dead rise not at all, why are they baptized for them? (Panarion Part 28, 6:4-5)

Although later writers would be condemnatory of the practice of baptism for the dead, Epiphanius presents it far more neutrally.

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Conclusion

Baptism for the dead is taught in the very early Christian writings as a means by which those who have died without the Gospel can, in the intermediate state, receive the blessings they had not the opportunity to obtain in this life.

Little is shared regarding the details of the process, but we can conclude:

• It was a baptism by immersion (from the Shepherd of Hermas)
• The baptisms were performed by proxy (from Paul & Epiphanius)
• This was part of the doctrine of salvation for those who had no opportunity to receive the Gospel in this life. This included the preaching of the Gospel to the dead & the provision of Gospel ordinances for them (from the Shepherd of Hermas, Clement, and others)

Not much.

1 Cor 15:29 has different interpretations depending on who you ask. Historically I think it can be shown that some people practiced baptisms for the dead as it was practiced/mentioned up to about 397 AD when it was banned in Council of Carthage, where it was discussed:

There were several meetings regarding Christian doctrine held in the city of Carthage in northern Africa. Prior to the Council of Nicea, the councils mostly discussed issues such as how to handle apostates, whether or not to accept unorthodox baptisms, and so forth¹

And

That the eucharist shall not be given to the bodies of the deceased; for it was said by the Lord, “Take and eat”; but a cadaver cannot “take” or “eat”. Then care must be taken also that the weakness of the brothers shall not believe that it is possible to baptise the dead, when he notices that the eucharist is not being given to the dead.²

Epiphanius of Salamis (~315 AD) said

6:4 For their school reached its height in this country, I mean Asia, and in Galatia as well. And in these countries I also heard of a tradition which said that when some of their people died too soon, without baptism, others would be baptized for them in their names, so that they would not be punished for rising unbaptized at the resurrection and become the subjects of the authority that made the world.

My belief is it comes down to if you accept the practice of vicarious work. If you believe Jesus can atone for people's sins, you believe in vicarious work. I'd argue it isn't much of a stretch to believe vicarious baptisms as valid practice. Vicarious work does not negate agency or personal choice-even though Christ atoned for our sins, we still sin and are responsible for our actions (though additional doctrine like the spirit world must also be accepted in the case of vicarious baptism).

_{1 What happened at Council of Carthage}

_{2 Acts of the Council of Carthage 397 and Council of Hippo 393 V1 2022, pg 7}

_{emphasis mine, many references started from wikipedia}

Bullinger says to read this as:

why are they baptized also?
(It is) for the dead. It is to remain dead, as Christ remains, if there be no resurrection, v. 13.
The argument is, What is the use of being baptized, if it is only to remain dead?
No suggestion here of the vicarious baptism which sprang up later among the Macionites and others.

baptism - What were the Corinthians doing when they "baptized on behalf of the dead"? - Biblical Hermeneutics Stack Exchange answers a similar question:

Short Answer: Paul was not in any way endorsing their action. On the contrary, Paul was bringing this up as evidence of their absurdity. The Corinthians were denying that the dead would be raised... but then they were turning around and getting baptized for them! His point is that they are being ridiculous.

Read the entire answer for a detailed explanation.

The other answers dig into the nature of this practice among heretical sects and such. I felt it was worthwhile to add this historical commentary on the verse, which lets you hear from the early church fathers themselves on what was going on with this practice:

[AD 200] Tertullian For if "as in Adam all die, even so in Christ shall all be made alive," [1 Corinthians 15:22] their vivification in Christ must be in the flesh, since it is in the flesh that arises their death in Adam. "But every man in his own order," because of course it will be also every man in his own body. For the order will be arranged severally, on account of the individual merits. Now, as the merits must be ascribed to the body, it must needs follow that the order also should be arranged in respect of the bodies, that it may be in relation to their merits. But inasmuch as "some are also baptized for the dead," [1 Corinthians 15:29] we will see whether there be a good reason for this. Now it is certain that they adopted this (practice) with such a presumption as made them suppose that the vicarious baptism (in question) would be beneficial to the flesh of another in anticipation of the resurrection; for unless it were a bodily resurrection, there would be no pledge secured by this process of a corporeal baptism. "Why are they then baptized for the dead," he asks, unless the bodies rise again which are thus baptized? For it is not the soul which is sanctified by the baptismal bath: its sanctification comes from the "answer." [1 Peter 3:21] - On the Resurrection of the Flesh, Chapter 48

[AD 215] Clement of Alexandria (quoting the teachings of Theodotus the Gnostic from AD 170) And when the Apostle said, "Else what shall they do who are baptised for the dead?"... For, he says, the angels of whom we are portions were baptised for us. But we are dead, who are deadened by this existence, but the males are alive who did not participate in this existence. "If the dead rise not why, then, are we baptised?" Therefore we are raised up "equal to angels," and restored to unity with the males, member for member. Now they say "those who are baptised for us, the dead," are the angels who are baptised for us, in order that when we, too, have the Name, we may not be hindered and kept back by the Limit and the Cross from entering the Pleroma. Wherefore, at the laying on of hands they say at the end, "for the angelic redemption" that is, for the one which the angels also have, in order that the person who has received the redemption may, be baptised in the same Name in which his angel had been baptised before him. Now the angels were baptised in the beginning, in the redemption of the Name which descended upon Jesus in the dove and redeemed him. And redemption was necessary even for Jesus, in order that, approaching through Wisdom, he might not be detained by the Notion of the Deficiency in which he was inserted, as Theodotus says. - Excerpta ex Theodoto, Section 22

[AD 220] Tertullian Let us now return to the resurrection, to the defense of which against heretics of all sorts we have given indeed sufficient attention in another work of ours. But we will not be wanting (in some defense of the doctrine) even here, in consideration of such persons as are ignorant of that little treatise. "What," asks he, "shall they do who are baptized for the dead, if the dead rise not?" [1 Corinthians 15:29] Now, never mind that practice, (whatever it may have been.) The Februarian lustrations will perhaps answer him (quite as well), by praying for the dead. Do not then suppose that the apostle here indicates some new god as the author and advocate of this (baptism for the dead. His only aim in alluding to it was) that he might all the more firmly insist upon the resurrection of the body, in proportion as they who were vainly baptized for the dead resorted to the practice from their belief of such a resurrection. We have the apostle in another passage defining "but one baptism." [Ephesians 4:5] To be "baptized for the dead" therefore means, in fact, to be baptized for the body; for, as we have shown, it is the body which becomes dead. What, then, shall they do who are baptized for the body, [Ephesians 4:5] if the body rises not again? We stand, then, on firm ground (when we say) that the next question which the apostle has discussed equally relates to the body. But "some man will say, 'How are the dead raised up? With what body do they come?'" [1 Corinthians 15:35] Having established the doctrine of the resurrection which was denied, it was natural to discuss what would be the sort of body (in the resurrection), of which no one had an idea. - Against Marcion, Book V, Chapter 10

[AD 384] Ambrosiaster It seems that some people were at that time being baptized for the dead because they were afraid that someone who was not baptized would either not rise at all or else rise merely in order to be condemned. - Commentary on Paul's Epistles, Corpus Scriptorum Ecclesiasticorum Latinorum 81.175

[AD 398] Didymus the Blind The Marcionites baptize the living on behalf of dead unbelievers, not knowing that baptism saves only the person who receives it. - Pauline Commentary From the Greek Church: Collected and Edited Catena Writings, page 8 - original source unclear

[AD 403] Epiphanius of Salamis In turn this Cerinthus, fool and teacher of fools that he is, ventures to maintain that Christ has suffered and been crucified but has not risen yet, but he will rise when the general resurrection of the dead comes. Now this position of theirs is untenable, both the words and the ideas. And so, in astonishment at those who did not believe in the coming resurrection of the dead, the apostle said, 'If the dead rise not, then is Christ not raised;' [1 Cor 15:16] 'Let us eat and drink, for tomorrow we die' [1 Cor 15:32] and, 'Be not deceived; evil communications corrupt good manners.' [1 Cor 15:33] Again, he likewise gives their refutation to those who say that Christ is not risen yet by saying, 'If Christ be not raised, our preaching is vain and our faith is vain. And we also are found false witnesses against God, because we testified against God that he raised up Christ, if so be that he raised him not up.' [1 Cor 15:14-15] For in Corinth too certain persons arose to say there is no resurrection of the dead, as though it was apostolic preaching that Christ was not risen yet and the dead are not raised (at all). For their school reached its height in this country, I mean Asia, and in Galatia as well. And in these countries I also heard of a tradition which said that when some of their people died too soon, without baptism, others would be baptized for them in their names, so that they would not be punished for rising unbaptized at the resurrection and become the subjects of the authority that made the world. And the tradition I heard of says that this is why the same holy apostle said, 'If the dead rise not at all, why are they baptized for them?' [1 Cor 15:29] But others explain the text satisfactorily by saying that, as long as they are catechumens, the dying are allowed baptism before they die because of this hope, showing that the person who has died will also rise, and therefore needs the forgiveness of his sins through baptism. Some of these people have preached that Christ is not risen yet, but will rise together with everyone; others, that the dead will not rise at all. Hence the apostle has come forward and given the refutation of both these groups and the rest of the sects at once on the subject of resurrection. And in the testimonies that he gave in full he produced the sure proof of the resurrection, salvation and hope of the dead 6:8 by saying, 'This corruptible must put on incorruption, and this mortal must put on immortality,' [1 Cor 15:33] and again, 'Christ is risen, the first fruits of them that slept.' [1 Cor 15:20] This was to refute both kinds of sects at once and truly impart the unsullied doctrine of his teaching to anyone who wanted to know God's truth and saving doctrine. - The Panarion, Part 28. Epiphanius Against the Cerinthians, Section 6

[AD 407] John Chrysostom Else what shall they do which are baptized for the dead? If the dead are not raised at all, why then are they baptized for the dead? He takes in hand again another topic, establishing what he said at one time from what God does , and at another from the very things which they practice. And this also is no small plea for the defense of any cause when a man brings forward the gainsayers themselves as witnessing by their own actions what he affirms. What then is that which he means? Or will you that I should first mention how they who are infected with the Marcionite heresy pervert this expression? And I know indeed that I shall excite much laughter; nevertheless, even on this account most of all I will mention it that you may the more completely avoid this disease: viz., when any Catechumen departs among them, having concealed the living man under the couch of the dead, they approach the corpse and talk with him, and ask him if he wishes to receive baptism; then when he makes no answer, he that is concealed underneath says in his stead that of course he should wish to be baptized; and so they baptize him instead of the departed, like men jesting upon the stage. So great power has the devil over the souls of careless sinners. Then being called to account, they allege this expression, saying that even the Apostle has said, "They who are baptized for the dead." Do you see their extreme ridiculousness? Is it meet then to answer these things? I trow not; unless it were necessary to discourse with madmen of what they in their frenzy utter. But that none of the more exceedingly simple folk may be led captive, one must needs submit to answer even these men. As thus, if this was Paul's meaning wherefore did God threaten him that is not baptized? For it is impossible that any should not be baptized henceforth, this being once devised: and besides, the fault no longer lies with the dead, but with the living. But to whom spoke he, "Unless you eat My flesh, and drink My blood, you have no life in yourselves?" [John 6:53] To the living, or to the dead, tell me? And again, "Unless a man be born again of water and of the Spirit, he cannot see the kingdom of God." [John 3:5] For if this be permitted, and there be no need of the mind of the receiver nor of his assent while he lives, what hinders both Greeks and Jews thus to become believers, other men after their decease doing these things in their stead? But not to prolong fruitless toil in cutting asunder their petty spiders' webs , come let us unfold unto you the force of this expression. What then is Paul speaking of? 2. But first I wish to remind you who are initiated of the response , which on that evening they who introduce you to the mysteries bid you make; and then I will also explain the saying of Paul: so this likewise will be clearer to you; we after all the other things adding this which Paul now says. And I desire indeed expressly to utter it, but I dare not on account of the uninitiated; for these add a difficulty to our exposition, compelling us either not to speak clearly or to declare unto them the ineffable mysteries. Nevertheless, as I may be able, I will speak as through a veil. As thus: after the enunciation of those mystical and fearful words, and the awful rules of the doctrines which have come down from heaven, this also we add at the end when we are about to baptize, bidding them say, "I believe in the resurrection of the dead," and upon this faith we are baptized. For after we have confessed this together with the rest, then at last are we let down into the fountain of those sacred streams. This therefore Paul recalling to their minds said, "if there be no resurrection, why are you then baptized for the dead ?" i.e., the dead bodies. For in fact with a view to this are you baptized, the resurrection of your dead body, believing that it no longer remains dead. And thou indeed in the words makest mention of a resurrection of the dead; but the priest, as in a kind of image, signifies to you by very deed the things which you have believed and confessed in words. When without a sign you believe, then he gives you the sign also; when you have done your own part, then also does God fully assure you. How and in what manner? By the water. For the being baptized and immersed and then emerging, is a symbol of the descent into Hades and return thence. Wherefore also Paul calls baptism a burial, saying, "Therefore we are buried with Him by baptism into death." [Romans 6:4] By this he makes that also which is to come credible, I mean, the resurrection of our bodies. For the blotting out sins is a much greater thing than the raising up of a body. And this Christ declaring, said, "For whether is easier to say, Your sins are forgiven, or to say, Take up your bed, and walk?" [Matthew 9:5] "The former is the more difficult," says He, "but since you disbelieve it as being hidden, and make the easier instead of the more difficult the demonstration of my power, neither will I refuse to afford you this proof." Then says He to the paralytic, "Arise, take up your bed, and go unto your house." "And how is this difficult," says one, "when it is possible to kings also and rulers? For they too forgive adulterers and homicides." You are jesting, O man, who sayest these things. For to forgive sins with God only is possible. But rulers and kings, whether it is adulterers whom they forgive or homicides, release them indeed from the present punishment; but their sin they do not purge out. Though they should advance to offices them that have been forgiven, though they should invest them with the purple itself, though they should set the diadem upon their heads, yet so they would only make them kings, but could not free them from their sin. It being God alone who does this; which accordingly in the Laver of Regeneration He will bring to pass. For His grace touches the very soul, and thence plucks up the sin by the root. Here is the reason why he that has been forgiven by the king may be seen with his soul yet impure, but the soul of the baptized no longer so, but purer than the very sun-beams, and such as it was originally formed, nay rather much better than that. For it is blessed with a Spirit, on every side enkindling it and making its holiness intense. And as when you are recasting iron or gold you make it pure and new once more, just so the Holy Ghost also, recasting the soul in baptism as in a furnace and consuming its sins, causes it to glisten with more purity than all purest gold. Further, the credibility of the resurrection of our bodies he signifies to you again from what follows: viz., that since sin brought in death, now that the root is dried up, one must not after that doubt of the destruction of the fruit. Therefore having first mentioned "the forgiveness of sins," you next confess also "the resurrection of the dead;" the one guides you as by hand on to the other. Yet again, because the term Resurrection is not sufficient to indicate the whole: for many after rising have again departed, as those in the Old Testament, as Lazarus, as they at the time of the crucifixion: one is bid to say, "and the life everlasting," that none may any longer have a notion of death after that resurrection. These words therefore Paul recalling to their minds, says, "What shall they do which are baptized for the dead?" "For if there be no resurrection," says he, "these words are but scenery. If there be no resurrection, how persuade we them to believe things which we do not bestow?" Just as if a person bidding another to deliver a document to the effect that he had received so much, should never give the sum named therein, yet after the subscription should demand of him the specified monies. What then will remain for the subscriber to do, now that he has made himself responsible, without having received what he admitted he had received? This then he here says of those who are baptized also. "What shall they do which are baptized," says he, "having subscribed to the resurrection of dead bodies, and not receiving it, but suffering fraud? And what need was there at all of this confession, if the fact did not follow?" - Homily 40 on First Corinthians

[AD 419] Council of Carthage of 419 ...neither the Eucharist nor Baptism should be given to the bodies of the dead. [Greek version adds: "For it is written: 'Take, Eat,' but the bodies of the dead can neither 'tak' nor 'eat'."] - Canon 18

[AD 1564] John Calvin "Else what shall they do" He resumes his enumeration of the absurdities, which follow from the error under which the Corinthians labored. He had set himself in the outset to do this, but he introduced instruction and consolation, by means of which he interrupted in some degree the thread of his discourse. To this he now returns. In the first place he brings forward this objection — that the baptism which those received who are already regarded as dead, will be of no avail if there is no resurrection. Before expounding this passage, it is of importance to set aside the common exposition, which rests upon the authority of the ancients, and is received with almost universal consent. Chrysostom, therefore, and Ambrose, who are followed by others, are of opinion that the Corinthians were accustomed, when any one had been deprived of baptism by sudden death, to substitute some living person in the place of the deceased — to be baptized at his grave. They at the same time do not deny that this custom was corrupt, and full of superstition, but they say that Paul, for the purpose of confuting the Corinthians, was contented with this single fact, that while they denied that there was a resurrection, they in the mean time declared in this way that they believed in it. For my part, however, I cannot by any means be persuaded to believe this, for it is not to be credited, that those who denied that there was a resurrection had, along with others, made use of a custom of this sort. Paul then would have had immediately this reply made to him: “Why do you trouble us with that old wives’ superstition, which you do not yourself approve of?” Farther, if they had made use of it, they might very readily have replied: “If this has been hitherto practiced by us through mistake, rather let the mistake be corrected, than that it should have weight attached to it for proving a point of such importance.” Granting, however, that the argument was conclusive, can we suppose that, if such a corruption as this had prevailed among the Corinthians, the Apostle, after reproving almost all their faults, would have been silent as to this one? He has censured above some practices that are not of so great moment. He has not scrupled to give directions as to women’s having the head covered, and other things of that nature. Their corrupt administration of the Supper he has not merely reproved, but has inveighed against it with the greatest keenness. Would he in the meantime have uttered not a single word in reference to such a base profanation of baptism, which was a much more grievous fault? He has inveighed with great vehemence against those who, by frequenting the banquets of the Gentiles, silently countenanced their superstitions. Would he have suffered this horrible superstition of the Gentiles to be openly carried on in the Church itself under the name of sacred baptism? But granting that he might have been silent, what shall we say when he expressly makes mention of it? Is it, I pray you, a likely thing that the Apostle would bring forward in the shape of an argument a sacrilege by which baptism was polluted, and converted into a mere magical abuse, and yet not say even one word in condemnation of the fault? When he is treating of matters that are not of the highest importance, he introduces nevertheless this parenthesis, that he "speaks as a man". (Romans 3:5; Romans 6:19; Galatians 3:15.) Would not this have been a more befitting and suitable place for such a parenthesis? Now from his making mention of such a thing without any word of reproof, who would not understand it to be a thing that was allowed? For my part, I assuredly understand him to speak here of the right use of baptism, and not of an abuse of it of that nature. Let us now inquire as to the meaning. At one time I was of opinion, that Paul here pointed out the universal design of baptism, for the advantage of baptism is not confined to this life; but on considering the words afterwards with greater care, I perceived that Paul here points out something peculiar. For he does not speak of all when he says, "What shall they do, who are baptized?" etc. Besides, I am not fond of interpretations, that are more ingenious than solid. What then? I say, that those are "baptized for dead", who are looked upon as already dead, and who have altogether despaired of life; and in this way the particle ὑπέρ will have the force of the Latin "pro", as when we say, "habere pro derelicto"; — "to reckon as abandoned" This signification is not a forced one. Or if you would prefer another signification, to be "baptized for the dead" will mean — to be baptized so as to profit the dead — not the living, Now it is well known, that from the very commencement of the Church, those who had, while yet catechumens, fallen into disease, if their life was manifestly in danger, were accustomed to ask baptism, that they might not leave this world before they had made a profession of Christianity; and this, in order that they might carry with them the seal of their salvation. It appears from the writings of the Fathers, that as to this matter, also, there crept in afterwards a superstition, for they inveigh against those who delayed baptism till the time of their death, that, being once for all purged from all their sins, they might in this state meet the judgment of God. A gross error truly, which proceeded partly from great ignorance, and partly from hypocrisy! Paul, however, here simply mentions a custom that was sacred, and in accordance with the Divine institution — that if a catechumen, who had already in his heart embraced the Christian faith, saw that death was impending over him, he asked baptism, partly for his own consolation, and partly with a view to the edification of his brethren. For it is no small consolation to carry the token of his salvation sealed in his body. There is also an edification, not to be lost sight of — that of making a confession of his faith. They were, then, baptized for the dead, inasmuch as it could not be of any service to them in this world, and the very occasion of their asking baptism was that they despaired of life. We now see that it is not without good reason that Paul asks, what they would do if there remained no hope after death? This passage shows us, too, that those impostors who had disturbed the faith of the Corinthians, had contrived a figurative resurrection, making the farthest goal of believers to be in this world, His repeating it a second time, "Why are they also baptized for the dead?" gives it greater emphasis: “Not only are those baptized who think that they are to live longer, but those too who have death before their eyes; and that, in order that they may in death reap the fruit of their baptism.” - Commentary on Corinthians - Volume 2, on 1 Corinthians 15:29-34

The above was taken from Historical Christian Faith Commentaries.

There is no textual evidence either in the Bible or anywhere else that indicates that Christians engaged in this practice. Given the importance that the Church placed on baptism and the huge volume of ink and velum consumed in writing about it, it is at least odd, and at most very instructive that the Early Church Fathers never once mention the practice.

The Didache, for example, is among the earliest extra-scriptural Christian document and is recognized as a comprehensive codification of church practices. The Didache never once even hints at the practices of baptism by proxy or baptism for the dead. Moreover, the FACT is that the entire body of text from the Anti-Nicene Fathers is silent on the issue. Given the fact that they DID write so much about baptism, it is quite telling that there is no written endors*m*nt or even vague support for this practice among Christians.

There was one second century sect, the Cataphrygians (Montanists), seem to have developed the practice of baptizing actual corpses based on a misunderstanding of this verse:

Vicarious baptisms for the benefit of the dead, practiced on the fringe of Christianity from the second century, illustrate the influence of this verse, but not Paul's meaning. Paul is arguing that if Jesus has not risen, then Christian faith, preaching, remission, hope, are all vain; so is "baptism for the dead." He cannot mean Christian baptism, for none of its conditions or benefits, as Paul expounds them, can be affirmed of the dead. Besides, the following phrase ("And as for us " NIV; "And we ourselves " neb) dissociates Paul and his colleagues from the practice.(Evangelical Dictionary of Theology, p. 119).

Also, the Mandeans were a 1st century Gnostic cult who lived mostly far to the East of Corinth, around modern day Iraq. The Mandeans claim to adhere to an ancient revelation that even antedates Judaism (not at all uncommon claim among Gnostics). They practiced a baptism for the dead. Then as now, however, this Gnostic cult was small, obscure and far away and was not likely to have been known to the Corinthians or even to Paul.

Getting to Paul's purpose in writing to the Corinthians appears to have been in response to several questions he had received. this is evident in his repeated use of the phrase "Now concerning...", followed by some topic upon which he expounds.

In the context of the passage, it is evident that Paul is simply pointing out the truth of Christ's lordship after the resurrection. In the process he ask a rhetorical question: "...and if the dead do not rise (as some likely believed), then what are THEY doing who baptize for the dead? Paul is preempting the objection that there IS nno resurrection over which Christ will reign.

Secondly, the grammar is crucial to understanding any passage and 1 Corinthians 15:29 is no exception on this rule. Paul's deliberate use of Greek conjugation of the verb "baptize", (Greek: "baptezo") is clearly indicative of a third person plural pronoun (variously translated "they", "those who", "those pe3ople" and "people in the general sense).

This is important, he is NOT claiming that the Corinthian Church is or should be baptizing for the dead, otherwise he would have used a first or second person plural conjugation of the verb ("what are YOU doing baptizing for the dead" or "what are WE doing baptizing for the dead"). He is clearly referring to someone ELSE - they, THOSE PEOPLE WHO do baptize for the dead.

Since the Christian church has NEVER baptized for the dead and since the Elusinian cult who served a pagan goddess likely DID baptize for the dead, Paul was most likely referring to the servants of Demeter, using them as a rhetorical example to make a much larger and more important point.

Finally, I give you Hebrews 9:27, "And inasmuch as it is appointed for men to die once and after this comes judgment." This verse alone eliminates the possibility of reincarnation and any sort of second chance at getting saved.

The passage under question is this.

Else what shall they do which are baptized for the dead, if the dead rise not at all? why are they then baptized for the dead? 1 Cor 15:29

Two things of note. Paul speaks of their (they) baptizing for the dead, not our (we) baptizing for the dead. The context of verse 29 is in relation to the end of death, to Christ's kingdom when God is all in all.

And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all. 1 Cor 15:28

With that in mind, we find a very early example of baptism for the dead in the heretic Marcion.

Marcion of Sinope practiced baptism for the dead.

The Marcionites practiced sometimes vicarious baptism for the dead. Schaff History

We also find Tertullian referring to it, not in support per se, but as an argument of resurrection in general, of the aforementioned God is all in all; that is, the idea of resurrection could be found in various other religions, besides Christianity. For him, obviously, Christianity was the true religion, but he used their baptism for the dead to draw them to the truth. This is how he understood Paul's comment.

Else what shall they do which are baptized for the dead, if the dead rise not at all? why are they then baptized for the dead?

Why are they baptized for the dead if they didn't believe in a bodily resurrection?

“What,” asks he, “shall they do who are baptized for the dead, if the dead rise not?” Now, never mind that practice, (whatever it may have been.) The Februarian lustrations will perhaps answer him (quite as well), by praying for the dead. Do not then suppose that the apostle here indicates some new god as the author and advocate of this (baptism for the dead. His only aim in alluding to it was) that he might all the more firmly insist upon the resurrection of the body, in proportion as they who were vainly baptized for the dead resorted to the practice from their belief of such a resurrection. Tertullian Against Marcion Book V

Again, for Christianity, for us, there is no sense of a baptism for the dead, but it is found elsewhere. In that, he forces the argument of the belief in a bodily resurrection.

So, to answer the OP, it appears to be a fairly wide, early practice, though not in the Christian Church. Tertullian's mention of "Februarian lustrations" refers to Lupercalia, an ancient Roman festival extant since 44 BC. The practice of "praying for the dead" and "baptism for the dead" appears to source there. The apostle was aware of it, but again, it was done by them, not us.