Did any in the Early Church require a kosher diet?

At the beginning of the Church, reading from the New Testament Book of Acts and the rest of the books onwards, you will see that at first believers/Christians consisted of mostly Jews. Later we see gentiles joining the faith.

Jewish Christians

• They practice law holidays/customs but also had faith in Jesus Christ
• Dietary laws were imposed by God through Moses
• They were first to receive Holy Spirit (Acts chapter 2)
• Peter saw later on that God even gave Holy Spirit to gentiles (Acts chapter 10)

Gentile Christians

• Paul was their apostle
• They were not bound to practice law customs but to glorify God by fruits of the spirit (Galatians chapter 5)
• They believed in Jesus Christ and at one point Jewish Christians wanted to impose customs on them but Paul spoke with the rest of the apostles that God's will was for men to not live in sin (flesh) but to live in the spirit
• Gentiles were encouraged not to eat food dedicated to idols but the rest of the diet is not enforced because what goes in the belly does not defile

As noted in the introduction to my answer to Why is there no archaeological evidence that Christians existed for 200 years after 70 AD? - Christianity Stack Exchange, the "early church" refers to a period of several centuries that contains a long gap with little historical record.

The lack of evidence of early Christianity has been noted by many scholars.

Edward Gibbon, in The History of the Decline and Fall of the Roman Empire, said :"The scanty and suspicious materials of ecclesiastical history seldom enable us to dispel the dark cloud that hangs over the first age of the church.".

William Fitzgerald, in Lectures on Ecclesiastical History said: "Over this period of transition, which immediately succeeds upon the era properly called apostolic, great obscurity hangs ...".

Samuel G. Green in A Handbook of Church History said: "The thirty years which followed the close of the New Testament Canon and the destruction of Jerusalem are in truth the most obscure in the history of the Church. When we emerge in the second century we are, to a great extent, in a changed world.".

William J. McGlothlin, in The Course of Christian History said: "But Christianity itself had been in [the] process of transformation as it progressed and at the close of the period was in many respects quite different from the apostolic Christianity.".

Jesse Lyman Hurlbut, in _Story of the Christian Church, said:"For fifty years after Paul’s life, a curtain hangs over the Church, through which we vainly strive to look; and when at last it rises, about 129 A.D. with the writings of the earliest Church Fathers, we find a Church in many ways very different from that in the days of Peter and Paul.".

Other historians make similar comments about the lack of historical material from that period, and how, after a few centuries, suddenly Christianity is seen to be flourishing, with no evidence of how it got that way.

Whatever happened, it was not a smooth transition.

That long gap in the historic record separates the apostolic Church of God in Jerusalem and the Catholic Church in Rome.

The question, "Did any in the early church require a kosher diet?" will receive two very different answers, depending upon which side of the transition one considers.

The Apostolic Church of God:

TLDR: No one wrote about requiring a kosher diet for the same reason that no one wrote about forbidding murder and theft. It was simply something that everyone took for granted, so there was no need to write about it.

The early church was entirely composed of Jews, so everyone naturally ate only kosher food.

Until Peter's vision (Acts 10 (NKJV)), in which he is told that Christianity is intended for all mankind, "… God has shown me that I should not call any man common or unclean", Christianity was entirely Jewish, the only difference being the belief that Jesus was the promised Messiah. Christians and Jews lived, worked, worshiped, and studied together.
— from my answer to Were there implicit laws not referenced in the Acts 15 letter to gentile believers?

Arguments are continually presented by modern Christians that the Church described in the Bible did eat non-kosher food, but they are all examples of eisegesis (reading what one already believes into the scripture). I won't discuss them here, but my answer to Why do most Christians eat pork when Deuteronomy says not to? refutes the most popular of these rationalizations:

• Initially, the prohibition against pork was part of the Law given to Moses [so it's binding only on Jews]
• Jesus declared all foods clean
• God told Peter that all meat was clean
• Peter said that nothing is unclean
• So let no one judge you in food or in drink
• It's only Old Testament

he Book of Acts records multiple instances of the apostles continuing to celebrate God's holy days, such as:

• Pentecost: 2:1, 20:16, 24:11, 1 Corinthians 16:87.
• Passover & Unleavened Bread: 12:3,4 20:6
• Day of Atonement: 27:9
• Unspecified: 18:20,21
• Sabbath: 13:14, 13:44, 16:13, 17:2, 18:4

Years after the Crucifixion, Peter claimed: "I have never eaten any thing that is common or unclean.".

Nowhere is there anything explicitly telling Christians to celebrate the holy days or to keep kosher. There was no need, as everyone already knew that they should.

Following Peter's vision, Gentiles were welcomed into the Church, creating three problems.

Until this point everyone was Jewish and everyone was part of God's covenant with Israel. (Historically, Gentiles did occasionally become Israelites, but they had to fully convert to Judaism.) But what about new Gentile proselytes, would they have to become part of the "old" covenant too? Many in the Church believed that this was true, that full conversion including circumcision was required.

Secondly, the transition from their previous Pagan lifestyle was quite extreme in some aspects For instance many Pagans were vegetarians or ascetics, and some members of the Church were forcing them to eat meat or to enjoy life. As a result, many potential converts were giving up because it was too much too soon.

Thirdly, those converts that had successfully adopted the Christian lifestyle were often shunned or ridiculed by their friends, families, and others in their previous life, and were in danger of lapsing back to their old lifestyle.

The Jerusalem Council resolved the first matter, saying that God's covenant with physical Israel was separate from God's covenant with spiritual Israel. There was no need for Gentiles to convert to Judaism in order to become Christians.

They also decided that initially, proselytes need only obey those laws that Judaism teach God gave to all mankind:

The Seven Laws of Noah include prohibitions against worshipping idols, cursing God, murder, adultery and sexual immorality, theft, eating flesh torn from a living animal, as well as the obligation to establish courts of justice. — Seven Laws of Noah - Wikipedia

…

Ignoring the four laws that almost all religions would consider obvious (blasphemy, murder, theft, injustice), and which the proselytes would already be following, leaves these three:

• Worshipping idols.
• Sexual immorality.
• Eating meat that has not bled to death (e.g. strangled or diseased, or still alive (oysters)).

These prohibitions correspond almost exactly to the list defined by the Council of Jerusalem.
— from my answer to Were there implicit laws not referenced in the Acts 15 letter to gentile believers?

The second and third problems were much more difficult, and many of Paul's epistles contained warnings about pushing proselytes too quickly and about being on the watch for outside influences. (Many of these writings are taken by many today to be the exact opposite, and claimed to somehow be about Christians that were following God's laws too closely.)

The Roman Church

TLDR: Anyone that suggested keeping a kosher diet would have been branded a heretic and Judaizer, and their writings would have been destroyed.

The original Christian Church didn't naturally grow into the Roman Church during that missing period of history. In fact, the Roman Church had existed long before Christianity.

Its leaders saw a threat from the rising popularity of this new Jewish sect, and initially tried to suppress it by force (e.g. "feeding Christians to the Lions in the Colosseum"). When this failed, they used a kind of syncretism to usurp the Christian Church. They assigned Christian names and meanings to their existing Gods and practices, and called themselves the Christian Church.

After that, anyone that developed a curiosity about Christianity would end up with the Roman Church, and anyone that tried to follow the original Christianity was branded as a heretic and a Judaizer. For more than a thousand years after that, whenever anyone studied the Bible, discovered its truths, and tried to revive the old religion, the entire organization was persecuted and killed.

See my answer to church history - What Pagan elements were adopted in christianity? - Christianity Stack Exchange.

And 2^nd century Statue of Isis — Wikipedia:Today's featured article/May 29, 2021.

See also my answers to other similar questions from Biblical Hermeneutics Stack Exchange:

• Did Jesus allow people to eat meat forbidden by Moses (Matthew 15)? No.
• Meaning of "food" and "drink" in Colossians 2:16 Nothing to do with kosher.
• Did Paul allow believers to eat meat of strangled animals in Colossians 2:16? No.
• Did Paul say to Timothy that it was okay to eat e.g., rabbit meat? No.
• Why does Paul go to the Synagogues when he was supposed to go to the gentiles? Because that's where the Christian Church used to meet and study.
• Is eating blood a sin according to Acts 15:20? Yes.
• Was Kosher Food the real issue in Galatians 2? No.
• Bible passages (like in Psalms) that seem legalistic (and maybe even sanctimonious) Vs Colossians verses warnings against legalistic behavior It is not a warning about legalistic behaviour.

Did any in the early church require a kosher diet?

Possibly and perhaps even probable, but I highly doubt that someone will be able to produce an actual source of information to confirm it.

One of the problems here is that the Early Church was a time of persecution and as such any possible sources of information have been lost over time. In times of persecution, one worries more about other things than preserving documentation as pertaining to kosher laws.

The Early Church is generally reckoned by church historians to begin with the ministry of Jesus (27–30 A.D.) and end with the First Council of Nicaea (325 A.D.). It is typically divided into two periods: the Apostolic Age (30–100 A.D.), when the first apostles were still alive) and the Ante-Nicene Period (100–325 A.D.).

As I already mentioned there is not a lot of historical information to be found in this period of time. See my response to this question: Why is there no archaeological evidence that Christians existed for 200 years after 70 AD?

There may not any historical evidence at hand, but the Ethiopian Orthodox Tewahedo Church, follows a very ancient tradition of observing many ancient Jewish Biblical kosher laws as prescribed in the Old Testament. There is no reason to presume that their traditions did not start in themselves in the Early Church. This may have been because of their isolation in regards to other Christian communities at that time and their closeness to the Jewish communities in Ethiopia.

Conversions in Ethiopia grew so rapidly in the first few centuries of [Christendom] (https://en.m.wikipedia.org/wiki/Christianization) that in 325 A.D., the Kingdom of Aksum (Modern Ethiopia and Eritrea) became the second country to declare Christianity as its official state religion after Armenia. To this day believers of the Ethiopian Church requires that one follows a kosher diet in some stricter than that of some Jewish communities.

Ethiopian Orthodox Tewahedo Church

Many traditions claim that Christian teachings were introduced to the region immediately after Pentecost. John Chrysostom speaks of the "Ethiopians present in Jerusalem" as being able to understand the preaching of Peter in Acts 2:38. Possible missions of some of the Apostles in the lands now called Ethiopia is also reported as early as the 4th century. Socrates of Constantinople includes Ethiopia in his list as one of the regions preached by Matthew the Apostle, where a specific mention of "Ethiopia south of the Caspian Sea" can be confirmed in some traditions such as the Roman Catholic Church among others. Ethiopian Church tradition tells that Bartholomew accompanied Matthew in a mission which lasted for at least three months. Paintings depicting these missions can be seen in the Church of St. Matthew found in the Province of Pisa, in northern Italy portrayed by Francesco Trevisan (1650–1740) and Marco Benefial (1688–1764).

The earliest account of an Ethiopian converted to the faith in the New Testament books is a royal official baptized by Philip the Evangelist (distinct from Philip the Apostle), one of the seven deacons (Acts, 8:26–27):

Then the angel of the Lord said to Philip, Start out and go south to the road that leads down from Jerusalem to Gaza. So he set out and was on his way when he caught sight of an Ethiopian. This man was a eunuch, a high official of the Kandake (Candace) Queen of Ethiopia in charge of all her treasure. (Acts, 8:26–27) The passage continues by describing how Philip helped the Ethiopian treasurer understand a passage from the Book of Isaiah that the Ethiopian was reading. After Philip interpreted the passage as prophecy referring to Jesus Christ, the Ethiopian requested that Philip baptize him, and Philip did so. The Ethiopic version of this verse reads "Hendeke" (ህንደኬ); Queen Gersamot Hendeke VII was the Queen of Ethiopia from c. 42 to 52. Where the possibility of gospel missions by the Ethiopian eunuch cannot be directly inferred from the Books of the New Testament, Irenaeus of Lyons around 180 AD writes that "Simon Backos" preached the good news in his homeland outlining also the theme of his preaching as being the coming in flesh of God that "was preached to you all before." The same kind of witness is shared by 3rd and 4th century writers such as Eusebius of Caesarea and Origen of Alexandria.

Early Christianity became the established church of the Ethiopian Axumite Kingdom under king Ezana in the 4th century when priesthood and the sacraments were brought for the first time through a Syrian Greek named Frumentius, known by the local population in Ethiopia as "Selama, Kesaté Birhan" ("Father of Peace, Revealer of Light"). As a youth, Frumentius had been shipwrecked with his brother Aedesius on the Eritrean coast. The brothers managed to be brought to the royal court, where they rose to positions of influence and baptized Emperor Ezana. Frumentius is also believed to have established the first monastery in Ethiopia, named Dabba Selama after him. In 2016, scientists excavated a 4th-century AD basilica (radio-carbon dated) in northeastern Ethiopia at a site called Beta Samati. This is the earliest known physical evidence of a church in sub-Saharan Africa.

Traditions

The faith and practice of Orthodox Ethiopian Christians include elements from Miaphysite Christianity as it has developed in Ethiopia over the centuries. Christian beliefs include belief in God (in Ge'ez / Amharic, ′Egziabeher, lit. "Lord of the Universe"), veneration of the Virgin Mary, the angels, and the saints, besides others. According to the Ethiopian Orthodox Church itself, there are no non-Christian elements in the religion other than those from the Old Testament, or Higge 'Orit (ሕገ ኦሪት),[citation needed] to which are added those from the New Testament, or Higge Wongiel (ሕገ ወንጌል). A hierarchy of Kidusan/ቅዱሳን (angelic messengers and saints) conveys the prayers of the faithful to God and carries out the divine will, so when an Ethiopian Christian is in difficulty, he or she appeals to them as well as to God. In more formal and regular rituals, priests communicate on behalf of the community, and only priests may enter the inner sanctum of the usually circular or octagonal church where the tabot ("ark") dedicated to the church's patron saint is housed. On important religious holidays, the tabot is carried on the head of a priest and escorted in procession outside the church. It is the tabot, not the church, which is consecrated. At many services, most parish members remain in the outer ring, where debteras sing hymns and dance.

Similarities to Judaism and Islam

The Ethiopian Church places a heavier emphasis on Old Testament teachings than one might find in Eastern Orthodox, Roman Catholic or Protestant churches, and its followers adhere to certain practices that one finds in Orthodox or Conservative Judaism. Ethiopian Christians, like some other Eastern Christians, traditionally follow dietary rules that are similar to Jewish Kashrut, specifically with regard to the slaughter of animals. Similarly, pork is prohibited, though unlike Rabbinical Kashrut, Ethiopian cuisine does mix dairy products with meat, which in turn makes it even closer to Karaite and Islamic dietary laws (see Halal). Women are prohibited from entering the church temple during menses; they are also expected to cover their hair with a large scarf (or shash) while in church, as described in 1 Corinthians, chapter 11. As with Orthodox synagogues, men and women sit separately in the Ethiopian church, with men on the left and women on the right (when facing the altar). (Women covering their heads and separation of the sexes in churches officially is common to some other Christian traditions; it is also the rule in some non-Christian religions, Islam and Orthodox Judaism among them).

Before praying, they wash their hands and face in order to be clean before and present their best to God; shoes are removed in order to acknowledge that one is offering prayer before a holy God. Ethiopian Orthodox worshipers remove their shoes when entering a church temple, in accordance with Exodus 3:5 (in which Moses, while viewing the burning bush, was commanded to remove his shoes while standing on holy ground). Furthermore, the Ethiopian Orthodox Tewahedo Church upholds Sabbatarianism, observing the seventh-day Sabbath (Saturday), in addition to the Lord's Day (Sunday), although more emphasis, because of the Resurrection of Christ, is laid upon Sunday.

The Ethiopian Orthodox Church calls for male circumcision, with near-universal prevalence among Orthodox men in Ethiopia. The Ethiopian Orthodox practice circumcision as a rite of passage, and they circumcise their sons "anywhere from the first week of life to the first few year".

The Ethiopian Orthodox Church prescribes several kinds of hand washing and traditionally follow rituals that are similar to Jewish netilat yadayim, for example after leaving the latrine, lavatory or bathhouse, or before prayer, or after eating a meal. The Ethiopian Orthodox Church observes days of ritual purification. People who are ritually unclean may approach the church but are not permitted to enter it; they instead stand near the church door and pray during the liturgy.

Interesting note also is that in Ethiopia, the new day starts at sundown, just as the Jewish tradition holds to this day!

Because Ethiopia is close to the Equator, daylight is pretty consistent throughout the year. So many Ethiopians use a 12-hour clock, with one cycle of 1 to 12 — from dawn to dusk — and the other cycle from dusk to dawn.

Most countries start the day at midnight. So 7:00 a.m. in East Africa Time, Ethiopia's time zone, is 1:00 in daylight hours in local Ethiopian time. At 7:00 p.m., East Africa Time, Ethiopians start over again, so it's 1:00 on their 12-hour clock. - If you have a meeting in Ethiopia, you'd better double check the time

The Ethiopian Church also claims that one of its churches, Our Lady Mary of Zion, is host to the original Ark of the Covenant that Moses carried with the Israelites during the Exodus.

Church of Our Lady Mary of Zion

Some years ago, I had the grace to encounter many Ethiopian priests that were traveling through our area and I assure you that they firmly believe that their dietary traditions go back to the very foundations of their Church. They see no reason to change their traditions... Nevertheless, they did not criticize others for their dietary rules or etiquette.

In the end, no one will be able find a source from the Early Church history that forbids non-kosher meat, since it is not immoral to follow such a tradition. Certainly Jewish converts would naturally keep to this biblical tradition. But after Peter’s vision of Acts 10:11 (Peter's vision of a sheet with animals) non kosher foods were permitted.

OP: Did any in the Early Church require a kosher diet?

Yes, the very early church after Christ's ascension went through three scriptural phases defined as Jerusalem, Judea, beyond, which would include certain early church writings.

The first phase encompasses the period from 30ad at Christ's ascension until about 3-4 years later with Saul's conversion into Paul and Peter's vision of clean and unclean as he visits Cornelius. These events would begin the expansion into the Gentile world. The point is the very earliest Christian converts were nearly completely Jewish and they continued to follow the Mosaic Law. Indeed, some would then apply the Law to Gentiles.

The second phase is when the apostles were moving primarily from Jerusalem into Judea and beyond. This expansion into the Gentile converts fueled the clash between those who thought Gentiles had to be circumcised and those who disagreed. This culminated about 50ad when they had their Jerusalem Council (Acts 15).

But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses. Acts 15:5

The teachers who mingled Law and Grace were a sect of the Pharisees. They were basically led by James, the Lord's brother.

To be clear, the question wasn't only about circumcision, but about keeping the whole Law. Paul put it this way.

For I testify again to every man that is circumcised, that he is a debtor to do the whole law. Gal 5:3

Circumcision was the entry way into the Mosaic covenant. If you get circumcised for that reason, then you are obligated to follow all of the Law. Christ then becomes as nothing for you.

So, during this 20-year or so phase there were Christians who taught you had to be circumcised and thus had to follow the dietary laws. By the way, it is a false division that calls out parts of the Law (ceremonial, dietary, ethical, salvific) as separate requirements from obeying the whole law (James 2:10, Deut 27:26).

In short, at this stage, some followed the Law, but others didn't. This then came to a head, leading to the Jerusalem Council.

For before that certain came from James, he [Peter] did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them which were of the circumcision. Gal 2:12

Peter knew better, but those from James were very impressive. As an aside, if indeed this is James the Lord's brother by same mother and different father, then we can more easily understand the dynamics of the situation.

After the Jerusalem Council that made clear a Christian didn't need to follow the Mosaic Law, the conflict took a back seat. After all, as Peter pointed out, no one can carry that yoke (except Christ).

From those phases based on scripture, we can move into early church fathers about the issue. We basically will find that it is heretics who continue to promote dietary laws for Christians. Christians are to be known by their love one for another, not from their diets.

Many of those, too, who belong to his [Saturninus} school, abstain from animal food, and draw away multitudes by a feigned temperance of this kind. Irenaeus AH Book I Chapter XXIV

Here is Tertullian to finish this off.

Now tell me, Marcion, what is your opinion of the apostle’s language, when he says, “Let no man judge you in meat, or in drink, or in respect of a holy day, or of the new moon, or of the sabbath, which is a shadow of things to come, but the body is of Christ?”6087 We do not now treat of the law, further than (to remark) that the apostle here teaches clearly how it has been abolished, even by passing from shadow to substance—that is, from figurative types to the reality, which is Christ. The shadow, therefore, is His to whom belongs the body also; in other words, the law is His, and so is Christ. If you separate the law and Christ, assigning one to one god and the other to another, it is the same as if you were to at472 tempt to separate the shadow from the body of which it is the shadow. Manifestly Christ has relation to the law, if the body has to its shadow. But when he blames those who alleged visions of angels as their authority for saying that men must abstain from meats—“you must not touch, you must not taste”—in a voluntary humility, (at the same time) “vainly puffed up in the fleshly mind, and not holding the Head,”6088 (the apostle) does not in these terms attack the law or Moses, as if it was at the suggestion of superstitious angels that he had enacted his prohibition of sundry aliments. For Moses had evidently received the law from God. When, therefore, he speaks of their “following the commandments and doctrines of men,”6089 he refers to the conduct of those persons who “held not the Head,” even Him in whom all things are gathered together;6090 for they are all recalled to Christ, and concentrated in Him as their initiating principle6091—even the meats and drinks which were indifferent in their nature. Tertullian Against Marcion Book V Chapter XIX

The point with these heresies was to try to divide the OT and NT, the shadow and reality in Christ. To return to Paul, if you follow the Law, Christ is for naught.

In sum, did any in the early church require a kosher diet? Yes, for about 3 1/2 years from Christ's ascension until Peter's vision and Saul's conversion. God had to intervene; the Good News is for all. Another 50 years and the conflict answering the question how is one justified came to a head in the Jerusalem Council. Subsequent to that for another 150 years, we find some still trying to force dietary laws, but they are found in the camps that do not agree that the God of the Old Testament is the same as the God in the New.