How is the belief that Christians are both adopted and begotten sons of God reconciled?

We can reconcile that Christians are both adopted and begotten sons of God because the Bible speaks of two births.

Jesus says to Nicodemus:

John 3:5,6 …except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.

Paul distinguishes between the substance of life and the subsistence of life, that which suffers loss and he whom even yet is saved:

1 Corinthians 3:13-15 Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is. If any man's work abide which he hath built thereupon, he shall receive a reward. If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire.

So we subsist in the Kingdom through adoption, yet the substance of our life must be begotten of the Father.

Jesus said:

John 5:19 …The Son can do nothing of himself, but what he seeth the Father do: for what things soever he doeth, these also doeth the Son likewise.

John 16:7-15 Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you…when the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come. He shall glorify me: for he shall receive of mine, and shall shew it unto you. All things that the Father hath are mine: therefore said I, that he shall take of mine, and shall shew it unto you.

The substance, which stands the test of fire is born of the Holy Spirit and begotten of the Father:

John 1:14…and the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father.)

Because Jesus is the, “only begotten of the Father” then whatever is begotten of the Father must then be Jesus Christ. "Followers of Christ” must then live like Paul:

Galatians 2:20 I am crucified with Christ: nevertheless I live; yet not I, but Christ lives in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me

There is no contradiction between those verses, and understanding that; is in Jesus’ reply to Nicodemus in John chapter 3.

John 3:1 through 8 KJV There was a man of the Pharisees, named Nicodemus, a ruler of the Jews: 2 The same came to Jesus by night, and said unto him, Rabbi, we know that thou art a teacher come from God: for no man can do these miracles that thou doest, except God be with him. 3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God. 4 Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born? 5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. 6 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. 7 Marvel not that I said unto thee, Ye must be born again. 8 The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit.

Let’s dissect Jesus’ answer and see how it explains the supposed conflict.

1. Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.

Genesis 2:7 KJV And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.

When man is born physically his soul is created at that time, and that soul/spirit is begotten of God.

But that soul is not acceptable to God because of sin. And even though that Soul is eternal in order to enter into The Kingdom of God it must be unblemished. And there is only one way that can be accomplished. That soul must be cleansed and that cleansing can only be accomplished through being born again, and that is where the Spiritual rebirth comes into play.

John4:14 KJV But whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life.

John 6:27 Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.

2. * That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.*

This may be the most difficult of Jesus’ answer to comprehend, in that our sinful nature (or as some call it sinful sou/spirit) must die and a new sinless nature (or soul/spirit) must be born.

a. *Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, *

This could easily be rewritten Labor not for those things which are only temporary, but for the things which lead to eternal life.

And the last part of his answer is where the adoption part takes place:

* which the Son of man shall give unto you: for him hath God the Father sealed.*

This new eternal life which is given by Jesus is not the eternal soul begotten at the birth of man, but is an entirely different pure and sinless eternal life, which begins when we accept Jesus sacrifice, because he takes on all our human sins , not only the sins of the past, but also present and any future sins.

Since we now have a sinless soul we are now acceptable to enter the Kingdom of God. And god will adopt our new sinless soul in replace of our old sinful soul.

3. Marvel not that I said unto thee, Ye must be born again.

Here Jesus is saying You should not be amazed that I tell you must be born again, you must be aware that no-one has kept the law in its entirety. It must be obvious that you have to start over and have a life which is free of sin.

4. Last of all Jesus describes what this new soul or Spirit is like.

   The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit.

Jesus is here saying when you receive this new soul/spirit it is like the wind you know it is there but you do not know where it came from nor do you realize that you will now be a part of God’s kingdom. In other words this new eternal life which is acceptable to God is something that is totally foreign to your old sinful person.

So the terms begotten and adopted are actually modifiers of the birth of a soul, and are the main point. That main point is that Jesus is the only begotten human who remained acceptable to God, but because of the new soul/spirit he gives us that cleansed, sinless soul/spirit is now a part of the Kingdom of God. And those Spirits can now join together with God and his only begotten son. The following Scriptures, which Jesus prayed at the last supper explain the concept of the Kingdom of God better than anything I might compose:

John 17:19 through 24 And for their sakes I sanctify myself, that they also might be sanctified through the truth. 20 Neither pray I for these alone, but for them also which shall believe on me through their word; 21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me. 22 And the glory which thou gavest me I have given them; that they may be one, even as we are one: 23 I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me. 24 Father, I will that they also, whom thou hast given me, be with me where I am; that they may behold my glory, which thou hast given me: for thou lovedst me before the foundation of the world.

That whole chapter of John 17 is well worth taking time to study in depth.

Catholic Perspective

Catechism of the Catholic Church In Brief 1279 brings together the terms birth into the new life and adoptive son of the Father

The fruit of Baptism, or baptismal grace, is a rich reality that includes forgiveness of original sin and all personal sins, birth into the new life by which man becomes an adoptive son of the Father, a member of Christ and a temple of the Holy Spirit. By this very fact the person baptized is incorporated into the Church, the Body of Christ, and made a sharer in the priesthood of Christ.

What is impossible with humans i.e. the inability for an adoptive parent to generate/give life to an adoptive child, the LORD, to whom nothing is impossible, does according to his good pleasure.

Therefore the explanation is in AND vs. OR i.e., God freely creating men in order to adopt them as his sons in his only-begotten Son and yet they are sons indeed because he communicates his own divine life to them¹ through the Son by the working of the Holy Spirit.

^{1. CCC 52 and 2 Pet 1:4.}

Further reading:

cf. Adopted children of God CCC 1, 52, 270, 294, 422, 654, 1709, 2009.

In NT times a father placed his own child under tutors until he reached maturity upon which time he was adopted by his own father and henceforward played a mature role in the family business. Paul is not meaning a process by which a child becomes a member of a family but an event when the child becomes a mature son. The adoption is the 'Son Placing' see Galatians 4. The adoption of the believer takes place at the resurrection it is the positioning of a child of God the Father into a place of maturity and responsibility. The creation is groaning and waiting for this adoption and the manifestation of the sons of God see Rom 8. A purpose of the adoption is for participation in the coming administration of the future age, see Eph 1:5-10 (particularly v10). Clearly, Paul is drawing from adoption as it was practised in NT times to reveal God's purpose for those sharing in Christ election and inheritance. The position of these glorified sons of God is also explained in Hebrews 2:5-10. A careful study of Galatians 4, Romans 8, Ephesians 1 and Hebrews 2 will make this clear.

How is the belief that Christians are both adopted and begotten sons of God reconciled?

There is a "begetting" associated with the new life we have in Jesus.

1 Peter 1:3-5 Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead, To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you, Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.

1 Corinthians 4:15 For though ye have ten thousand instructors in Christ, yet have ye not many fathers: for in Christ Jesus I have begotten you through the gospel.

There is a perspective of having been adopted in that we were in a state of no relation to God and then by being begotten now have a relationship with God as father.

Romans 8:15 For ye have not received the spirit of bondage again to fear; but ye have received the Spirit of adoption, whereby we cry, Abba, Father.

Humans can either give life to a son or adopt that son. The Bible gives us a picture of God who can do both. In giving us new life in Jesus, he is adopting us as sons. Adoption and begetting may be two ways of looking at the same thing.

We reconcile the fact that Christians are said to be both begotten/born again and adopted by acknowledging the different natures of the "begetting" with regards to being born again and adopted.

Born again refers to the beginning of spiritual life. See John 3:1-14. Our flesh is begotten of Adam, the flesh, and man. Since flesh and blood can not inherit the Kingdom of God (1 Corinthians 15:50), we require a second birth, a spiritual one, in order to enter into the Kingdom of God. In Messiah, we are not born of the flesh but born in the Spirit (see John 3:1-14). "In Christ" means because of our full inclusion in his body even before we were born and because of his action, ministry, and identity.

Adopted refers to our legal standing of relationship with God. God decided in advance to adopt us into his own family by bringing us to himself through Jesus Christ, since he adopted us by choosing to include us in Messiah even before our own first births. This is what he wanted to do, and it gave him great pleasure (Ephesians 1:5). This legally binding adoption is multifaceted and dictates our inheritance, our authority, and our relationship with the Father in his Kingdom.

We are sons of God both as an accident of our adoption as sons and our inclusion in the body of Messiah which are simultaneous but not synonymous with our second birth.

No one can say "I am begotten of God" unless he can say "I have been born again," because if he has not been born again, then he is begotten of Adam, indeed even of the devil (John 8:44), but he is not begotten of the Father, because that born of the flesh is flesh and that born of the Spirit is spirit (John 3:6). We were included in Messiah when we heard the message of truth, the gospel of our salvation. When we believed, we were marked in Messiah with a seal, the promised Holy Spirit. (Ephesians 1:13). So, spiritual birth and adoption to sonship are distinct but simultaneous immediate consequences of the action of God upon our experience and our persons.

Now, let us look at the structure of the Greek from John 1:12-13 (verse 13 is missing in the Greek text in some manuscripts):

ὅσοι δὲ ἔλαβον αὐτόν ἔδωκεν αὐτοῖς ἐξουσίαν

but as many as received him he gave to them authority

τέκνα θεοῦ γενέσθαι

children of God to become

τοῖς πιστεύουσιν εἰς τὸ ὄνομα αὐτοῦ

to those trusting on the name of him

οἳ οὐκ ἐξ αἱμάτων οὐδὲ ἐκ θελήματος σαρκὸς

the ones who not from blood nor from will of flesh

οὐδὲ ἐκ θελήματος ἀνδρὸς ἀλλ᾽ ἐκ θεοῦ ἐγεννήθησαν

nor from will of man but from God were begotten

The sentence structure of the Greek Scriptures tends to be very repetitive, especially John’s Narration in the first chapter. Recall how repetitive the clauses are at the opening:

“In the beginning was the logos and the logos was with God and God was the logos this one was in the beginning with God all through him existed and apart from him existed not even one which exists.”

There are two similarly repetitive phrases in John1:12-13, each starting with a (logical- not grammatical) conditional clause. They are related by “he gave them authority to become,” (denoted below by --> ). Though it’s only written in the first phrase, and implied in the second. This is common. The similar phrases are:

1. To those who received him --> children of God
2. To those trusting on the name of him --> the ones not from blood … but from God were begotten

That is, "to the ones who received him who trust in his name he gives the authority to become children of God, they who not from blood nor will of flesh nor will of man but from God were born"

The notion of sonship (or being sons of God, or being of God) always refers to this adopted status through Christ for the righteous in him, indeed:

Galatians 4:23

But the one indeed of the slave woman according to the flesh is begotten, but the one of the free woman through the promise.

ἀλλ’ ὁ μὲν ἐκ τῆς παιδίσκης κατὰ σάρκα γεγέννηται, ὁ δὲ ἐκ τῆς ἐλευθέρας διὰ τὴς ἐπαγγελίας.

Those who are brought in through the promise were originally sons of Adam (here Hagar), from whom we inherited our flesh. By the promised Messiah has made it possible for us to be included in him with the Father as he abides in him, to inherit our glory- the right to be called the sons of God, and to be so by the law according to his adoption and by the body in Messiah. Ordinarily, if a father were to adopt so many sons, the inheritance of the principle among them would decrease every time. But in our Father's house there are many rooms, and our inheritance is the principle among the sons, Jesus the Messiah (Rev 21) which does not decrease.

George MacDonald confronted the same dilemma in his Unspoken Sermons (Abba, Father!).

When a heart hears — and believes, or half-believes — that it is not the child of God by origin, from the first of its being, but may possibly be adopted into his family, its love sinks at once in a cold faint: where is its own father, and who is this that would adopt it? ...
The refusal to look up to God as our Father is the one central wrong in the whole human affair; the inability, the one central misery... 'Is God then not my Father,' cries the heart of the child, 'that I need to be adopted by him? Adoption! That can never satisfy me. Who is my father? Am I not his to begin with? Is God not my very own Father? Is he my Father only in a sort or fashion — by a legal contrivance? Truly, much love may lie in adoption, but if I accept it from any one, I allow myself the child of another! The adoption of God would indeed be a blessed thing if another than he had given me being! but if he gave me being, then it means no reception, but a repudiation. — "O Father, am I not your child?"'

MacDonald argues that the fact we are created in God's image is evidence that we are truly born as His children:

'Alas!' cries the child, 'if he be not my father, he cannot become my father. A father is a father from the beginning... the very origin of my being — alas, if he be only a maker and not a father! Then am I only a machine, and not a child — not a man! It is false to say I was created in his image!'

He then attempts to repudiate the position that we lost our birthright in the fall, saying that we are still "creature[s] of God," though we are evil. Anything else would mean that God turned his back and repudiated us, but we know this to be false because of the love He has shown in Jesus.

MacDonald believed that if we were not God's children, adoption would in fact be impossible:

'I could not even be adopted if I were not such as the adoption could reach — that is, of the nature of God. Much as he may love him, can a man adopt a dog?'

MacDonald considers the word generally translated as "adoption" (niothesia) in the Scriptures to be a mistranslation (or at least, a bad translation). Paul is not speaking of adoption, but a change in status; it would be more accurate to say that we have "graduated" into a sonship.

'Our English presentation of his [Paul's] teaching is in this point very misleading... In the New Testament the word is used only by the apostle Paul. Liddell and Scott give the meaning — "Adoption as a son," which is a mere submission to popular theology: they give no reference except to the New Testament. The relation of the word niothesia to the form thetos, which means "taken," or rather, "placed as one's child," is, I presume, the sole ground for the so translating of it: usage plentiful and invariable could not justify that translation here, in the face of what St. Paul elsewhere shows he means by the word. The Greek word might be variously meant — though I can find no use of it earlier than St. Paul; the English can mean but one thing, and that is not what St. Paul means. "The spirit of adoption" Luther translated "the spirit of a child;" adoption he translates kindschaff, or childship.'
Of two things I am sure — first, that by niothesia St. Paul did not intend adoption; and second, that if the Revisers [that is, translators] had gone through what I have gone through because of the word, if they had felt it come between God and their hearts as I have felt it, they could not have allowed it to remain in their version.

He concludes:

Once more I say, the word used by St. Paul does not imply that God adopts children that are not his own, but rather that a second time he fathers his own; that a second time they are born — this time from above; that he will make himself tenfold, yea, infinitely their father: he will have them back into the very bosom whence they issued, issued that they might learn they could live nowhere else; he will have them one with himself. It was for the sake of this that, in his Son, he died for them.

I love this question!!! I admit, when I first read your question, my immediate thought was that they are two separate metaphors. But I was checked immediately--we really are born spiritually into God's family. We really are adopted as his sons. Having thought about it some more, I offer this solution:

Luke 3:38 reads, "the son of Enosh, the son of Seth, the son of Adam, the son of God."

Adam was created a son of God. All who were born after him were born as sons of man. (except Jesus who was the Son of God (came down from God) born of a woman thus also the son of man). To become sons of God everyone else must be born spiritually which equals adoption as a son of God (which we were not originally). Below is my work:

All references to "sons of God" in the OT have been believed to be references to angels (also created directly by God as Adam was and who do not reproduce) I have included one from the NT referring to the angels as sons of God.*

Genesis 6:2 that the sons of God saw the daughters of men, that they were beautiful; and they took wives for themselves of all whom they chose.

Genesis 6:4 There were giants on the earth in those days, and also afterward, when the sons of God came in to the daughters of men and they bore children to them. Those were the mighty men who were of old, men of renown.

Job 1:6 Now there was a day when the sons of God came to present themselves before the LORD, and Satan also came among them.

Job 2:1 Again there was a day when the sons of God came to present themselves before the LORD, and Satan came also among them to present himself before the LORD.

Job 38:7 When the morning stars sang together, And all the sons of God shouted for joy?

Luke 20:36 nor can they die anymore, for they are equal to the angels and are sons of God, being sons of the resurrection.

Hosea 1:10 is an exception not referring to angels; It, however, speaks of the future when Isreal will be called "sons of God."

Then we hit the New Testament and read a promise that the peacemakers will be called sons of God:

Matthew 5:9 Blessed are the peacemakers, For they shall be called sons of God.

Then, after the death and resurrection we find people being "Sons of God."

Romans 8:14 For as many as are led by the Spirit of God, these are sons of God.

Romans 8:19 For the earnest expectation of the creation eagerly waits for the revealing of the sons of God.

Galatians 3:26 For you are all sons of God through faith in Christ Jesus.

So, we are born naturally as sons of man. In order to become sons of God we must believe in Christ Jesus. This is being born again spiritually. Thus while we are re-born spiritually as Sons of God, we were not originally born as sons of God. Thus, through faith in Christ we are adopted as sons:

Romans 8:15 For you did not receive the spirit of bondage again to fear, but you received the Spirit of adoption by whom we cry out, "Abba, Father."

Romans 8:23 Not only that, but we also who have the firstfruits of the Spirit, even we ourselves groan within ourselves, eagerly waiting for the adoption, the redemption of our body.

Romans 9:4 who are Israelites, to whom pertain the adoption, the glory, the covenants, the giving of the law, the service of God, and the promises;

Galatians 4:5 to redeem those who were under the law, that we might receive the adoption as sons.

Ephesians 1:5 having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will,

Yeshua is he only begotten son of God. Christians are called "begotten" sons when the only begotten son dwells in them. Paul said:

For those who have been baptized in the name of Christ have been clothed with Christ. (Galatians 3.27)

And John said:

Whoever is born of God does not commit sin because God's Seed is in him; and he cannot sin because he is born of God. (1Jhn. 3.9)

I think here John refers to the only begotten son as the Seed of God. And in that way Christians are called "begotten" sons; because God's Seed is inside of them. They have been clothed with Christ the Son.