I was startled. This question may seem odd, and it is, but a radio host, who is normally an excellent teacher, said the Second Person of the Trinity became the Son of God at his birth.
The issue is not one radio host, but the theology itself. So let’s leave him out of it and focus on the doctrine.
This doctrine is a variation on Adoptionism, which says that the God adopted Jesus at his birth or at his baptism or another point in time. Let’s call the variation Adoptionism-plus or Adoptionists-plus.
Luke 1:35 says: “So the holy one to be born will be called the Son of God.” Adoptionists-plus says that they can’t find Scripture that clearly says he was the Son of God before his incarnation. Yes, he was God before the incarnation (John 1:1-4), but the Scriptures are not clear about the title “Son of God” before his birth.
So let’s begin.
1.. Eternity past, earthly ministry, and eternal exaltation
In eternity past, he was the Son of God.
John 1:18 says: “No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known.” It seems the Father was in heaven with his Son before the incarnation and birth. See John 1:14 as well.
John 3:16 says that God sent his Son. It seems that this verse affirms that Jesus was the Son before he was sent.
Heb. 1:2 says: “but in these last days he has spoken to us by his Son, whom he appointed heir of all things, and through whom also he made the universe.” That verse says that the Son was the person through whom God made the universe. He was the Son before creation, long before his birth.
1 John 5:20 says: “And we are in him who is true by being in his Son Jesus Christ. He is the true God and eternal life.” This verse teaches that his Sonship is the same as his “Godness.” It seems odd that Jesus was always God, but not always the Son. Rather, he was eternally both.
Col. 1:9-20 is particularly clear that Jesus was the Son before creation and earth-time, that is, in eternity past: This is my translation. I add my comments in brackets:
9 Because of this, we also, from the day we heard [of it], have not stopped praying for you and asking that you would be filled with the knowledge of his will in all wisdom and spiritual understanding, 10 to walk worthily of the Lord, to please [him] fully, in every good work, producing fruit and growing in the knowledge of God, 11 [you Colossians] being empowered with all might according to the power of his glory, for all perseverance and patience; with joy 12 [Colossians] giving thanks to the Father who qualified you [Colossians] for a [actually “the”] share of the inheritance of the saints in the light, 13 who [Father] rescued us from the authority of darkness and transferred us into the kingdom of his beloved Son, 14 in whom [shifts to Son, the nearest antecedent] we have redemption, the forgiveness of sins, 15 who [Son, not God] is the image of the invisible God, firstborn [Sonship again] over all creation, 16 [why the firstborn?] for all things were created by him [Son], in heavens and on earth, visible and invisible, whether thrones or dominions, whether rulers or authorities—all things were created through him and for him; 17 and he [Son] is before everything and everything consists in him, 18 and he [the Son is still the subject of these clauses] is the head of the body, the church, who [Son] is the beginning, the firstborn from the dead, so that he [Son] would be preeminent in everything, 19 because in him [Son] all the fullness [of God; cf. 2:9] was pleased to dwell, 20 and through him [Son] to reconcile all things to himself [God or Christ, probably God, so there’s a shift], making peace through the blood and his [Son’s] cross—whether on the earth or in heavens. (Col. 1:9-20, my tentative translation)
That long passage is stark and clear. He was the Son before creation, that is, before his earthly birth.
On earth, he was born the Son of God and had this title throughout his ministry.
As noted, Luke 1:35 says that he shall be called the Son of God (implied: he was not the son of Joseph, but Jesus’s conception was of God).
Throughout his ministry, he was called the Son of God by people (Matt. 14:33; 27:54; Mark 1:1 John 1:49), demons and even Satan (Matt. 4:3, 6; 8:29; Mark 3:11). Of course his Father called him his Son (Matt. 3:17; 17:5).
He was appointed the Son of God with power at his resurrection (Rom. 1:4 Acts 13:33). He was already the Son, but his resurrection confirmed it with power.
In heaven he is the high priest, and Hebrew 5:5 seems to say that at this moment he is called God’s Son (cf. 5:9; 7:28): “In the same way, Christ did not take on himself the glory of becoming a high priest. But God said to him, ‘You are my Son; today I have become your Father.’” (Heb. 5:5)
Therefore Jesus was always the Son of God and will always be the Son of God, in eternity past, while he was on earth, and in eternity future.
Adoptionists-plus agree that he will be the Son for all eternity future and was the Son of God during his ministry. However, they say that the NT authors didn’t know about the Sonship of Christ until he was born; therefore he was not the Son in eternity past because he became the Son only after he was born! The NT authors merely projected the title “Son” in their epistles for convenience, not because he was actually the Son before his birth.
Apparently, Adoptionists-plus wants the NT authors to write something like this (boiled down):
The Father existed as the Father before creation. The Son existed as the Son before creation.
Instead, they wrote (boiled down):
The Father existed before creation (John 1:18; 1 Cor. 8:4; Eph. 3:14-15). The Son existed before creation. (John 1:18; Col. 1:14-17)
2.. Old Testament references to the Father
Further, the following verses hint that God was the Father before Jesus was born: Deut. 32:6, 18; Ps. 68:5; Is. 9:6; 63:16; 64:8; Jer. 3:4, 19; 31:9. Further, God was the Father and Creator of people (Deut. 32:6), so this is a hint that he has the role or title in heaven.
However, Adoptionism-plus could say that he is the Father in relation to the Israelites; there is no evidence in those verses that he was eternally the Father.
3.. References to the Father before creation
In Eph. 3:14-15 we read: “For this reason I kneel before the Father, from whom every family in heaven and on earth derives its name. So his Fatherhood is lifted from the earth to the families in heaven. where eternity exists.
However, Adoptionism-plus could say that his Fatherhood began when he made the families in heaven, a moment in time, not in eternity past.
1 Cor. 8:6 reads: “one God, the Father, from whom all things came and for whom we live.” A Father has to have at least one child, and the Son of God fits the role–all before creation.
Further, Adoptionism-plus could again claim that since the NT authors didn’t know about these titles / attributes until Jesus was born, they proleptically (“forward-fitted”) applied the title / attribute “Son” and “Father” to their later writings after they found out about it, either by personal revelation or the birth and life of Christ. So the Father was not eternally the Father.
4.. Restrictive v. expansive interpretations
Moreover, here are other opposite angles that Adoptionism-plus and everyone else could take:
Adotptionists: proleptically (by “forward-fitting”), the NT writers of the epistles used the title “Son,” but Luke 1:35 restricts their use of the term; he did not exist as Son before creation. He acquired the title at his birth.
Everyone else: analeptically (retrofitting), Col. 1:14-17 (and other verses) expands our interpretation of Luke 1:35 and our knowledge that he was the Son before creation. “Oh, now I see it! The angel told Mary only that her son shall be called the Son of God at his birth. He did not get in a theology lesson with her!”
I’m sure that is Adoptionism-plus (so far).
5.. Reply to prolepsis and analepsis
From our tiny, puny human point of view, everything we learn about God is proleptic or analeptic (or whatever), whether we learn about him through Scripture or our personal experience.
God is merciful (or holy or you pick one). We learn about his attribute from Scripture and perhaps from our personal experience. It seems odd that we cannot reason retrospectively (analeptically) and conclude that God has always been merciful, eternally. It seems odd that our way back (by reasoning) into eternity where God lives is blocked, because to do so would be proleptic or analeptic and eisegetical or something. It seems odd to conclude that God was not eternally merciful because he didn’t need to show mercy or have this attribute until humans came along and messed up and needed mercy! As if there was a point in time when he became merciful, when humans messed up!
Instead, we indeed can reason by reverse-engineering that God has always, eternally, been merciful (or love or holy). It is impossible to believe that God would add attributes to his essence as time went on. Maybe when the kingdom age comes, the Father will shed many attributes like mercy because renewed people in their glorified body will no longer need mercy and other such attributes!
In the same way, God the Father has always, eternally, been the Father, and God the Son has always been the Son. We apply the same logic (either by prolepsis or analepsis) about their Fatherhood and Sonship as we do about his being merciful–eternally Father and Son.
Therefore, we don’t need to require the NT authors to write: “The Father existed as Father before creation. The Son existed as Son before creation.” I can see now that the NT authors did not have the urgent need to be sooooo preeeee-cise! Instead, they simply wrote: “The Father existed before creation. The Son existed before creation.”
I think modern interpreters demand too much of the NT writers (and especially the OT writers, and especially Gen. 1-11! But that’s another issue).
6.. Other titles acquired during Jesus’s ministry
However, Adoptionism-plus could once again reply with some reason behind it: Jesus acquired the following name and titles at his birth or during his ministry: Jesus, Son of man (his self-designation), Son of David, Prophet, and Christ. And likewise he acquired his title Son at his birth (Luke 1:35). “Son” and “Father” are titles and can be acquired at a point in time, say, at the Son’s birth, whereas mercy and holiness and love are essential; they properly belong to God, and so they are eternal because they are essential.
My reply is that we should narrow down the field of other titles of the Second Person of the Trinity to compare them with the title of “Son.” Specifically, the titles other than “Christ” pretty much disappeared after Jesus’s life (but see Acts 7:56, for Son of man in church preaching; Rev. 1:13 and 14:14 use it, but probably in reference to Dan. 7:13; and see Rom. 1:3 for “descendant of David”). Those titles simply spoke of his ministry and mission in a Jewish setting about four decades before the destruction of the temple in A.D. 70. The few other times they appeared in preaching or in the epistles does not mean their uses were widespread.
My further reply: There is no special and intimate match up between those titles and God as there is in the Father-Son relationship.
Examples of pairings:
Son of Man / God (not the Heavenly Son of Man!)
Prophet / God (not the Heavenly Prophet!)
Son of David / God (the Heavenly Father of David may be implied, but the NT does not use it)
Christ (“the Anointed One”) / God (Heavenly Anointer may be implied, but the NT does not use it; see more about this below)
No NT writers paired them up like the list above.
Rather, as noted, this pairing works much better, and the NT writers latched on to it:
Son / Father
The Son acquired those titles in the list after he was incarnated. He got a human nature and grew into his ministry and acquired those other titles. In contrast, the Father was never incarnated, so he did not acquire additional titles, like Father or Heavenly Prophet and such like.
7.. Is the name “Jesus” and the title “Christ” special cases?
Now what about the title “Christ” and his name “Jesus”? As far as I can tell, only three passages seem to say that they appear, at first glance, to have existed before creation:
In your relationships with one another, have the same mindset as Christ Jesus: Who, being in very nature God, did not consider equality with God something to be used to his own advantage …. (Phil. 2:5-6, NIV).
But Paul uses the title “Christ Jesus” in reference to the Philippians who should have the same attitude as Jesus did, in his humbling of himself. I see no precise theology about the eternality of the title Christ or his name Jesus (but we saw this in Col. 2:9-20, see above). True, if Paul had said “Son” instead of “Christ Jesus,” then his theology would have been neat and tidy. However, he was simply following custom for the sake of clarity for the Philippians without fussy precision.
Note the title of my post. If I had been more precise, I should have written: “When did the Second Person of the Trinity ‘Become’ the Son of God?” But the point has been made by using the name of Jesus. No need for fussy precision.
In 1 Cor. 8:6 Paul writes: “one Lord, Jesus Christ, through whom all things came and through whom we live.” As noted, everything would have been neat and tidy, if Paul had written “Son.” However, I wonder sometimes whether the title “Christ” (and “Lord” and his name “Jesus”) was used so frequently that the NT writers were not very precise about it. They used it out of custom or habitual use for the sake of clarity for the Corinthians. And sometimes Jesus’s title “Lord” corresponds to the title LORD or YHWH in the OT, so it is also questionable that he acquired this title during his birth and life.
For a table of examples Lord (NT) and Lord and LORD (OT), please see this post:
Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ. For he chose us in him before the creation of the world to be holy and blameless in his sight. (Eph. 1:3-4, NIV)
That passage indicates where our salvation is found in our lives today: in Christ; even before the creation of the world God foresaw our salvation in Christ in the future. The verses do not necessarily say that the title or his name existed before creation.
8.. Are the terms Father / Son simply anthropomorphic?
Finally, Adoptionists-plus could say that the Father / Son relationship is simply an anthropomorphism, so we can relate to them better. (Anthropomorphism is a fancy word for viewing God from a human perspective by attributing to him human characteristics like hands and eyes. In this case he is Father and Son.)
In reply, how far does this line of reasoning go? Elohim is the standard word for “God,” but in some cases it can be translated as human rulers (Ex. 21:6; 22:8-9; Ps. 45:6). Maybe “gods” or “God” is just an anthropomorphism for judges and rulers, and the OT writers projected them in their own minds to be the ultimate Ruler and Judge: God. And the fictitious, empty idea stuck because of convenience.
Also, maybe Lord, both adonai (lord or Lord) and LORD, are anthropomorphisms derived from a Sumerian lord sitting in his palace. The biblical writers simply anthropomorphized the title to the ultimate LORD, just out of convenience, so this fictitious, empty idea also stuck.
Some Christians believe that any word or all languages combined are inadequate to describe God.
Maybe we should address “God” like this: ________ (blank). “Heavenly _____ I thank thee ….”
In reply, all of this line of reasoning is needless and extreme. God revealed himself in Scripture, which was written in a language that ordinary people can understand (in most verses).
Further, worst of all, by saying the Father-Son relationship is merely anthropomorphic, we obliterate the real distinctions between the first two persons of the Trinity. And now we could mix up the order. Why not say that the Second Person should become the First on the even number of days of the month, while the First and Second Persons remain the traditional way on the odd days?
By overthinking these matters, people get confused, and sowing confusion into the Body of Christ with oddball teaching is a no-no (1 Cor. 3:10-17)
By reverse-engineering (analepsis) there is enough biblical evidence to affirm that the Trinity’s Fatherhood and Sonship are not new or tacked on only at the exact moment the Second Person was conceived in the womb or at his baptism. Their Fatherhood and Sonship are every bit of who they are as their mercy and love and holiness (etc.) are. Since Fatherhood and Sonship are essential to who they are, the titles are eternal and cannot be added or shed.
By reverse-engineering (analepsis) and forward-engineering (prolepsis), the Trinity has been, is, and shall forever be the Father, the Son, and the Holy Spirit, eternally!
So how do I get to know Jesus more deeply?
The title “the Son of God” is an indispensable description of the Second Person of the Trinity. No Christian should abandon it and reduce the Second Person to a mere human prophet or teacher or rabbi or human son of man or messenger or make him so distant that they were to call him merely “the Second Person.” Rather, his Sonship reveals who he eternally was in relation to his Father. Now he shows us who his Father was.
The Second Person of the Trinity was never adopted as the Father’s Son, nor did he acquire the title “Son” at his birth or conception. He was eternally the Son.
However, we humans can be adopted. We can become the Father’s sons and daughters.
For those who are led by the Spirit of God are also the children of God. The Spirit you received does not make you slaves so that you live in fear again; rather, the Spirit you received brought about your adoption to sonship. And by him we cry, “Abba, Father!” The Spirit himself testifies with our spirit that we are God’s children. Now if we are children, then we are heirs—heirs of God and co-heirs with Christ, if indeed we share in his sufferings in order that we may also share in his glory. (Rom. 8:14-17)
Those verses are full of truths that can transform you. You are his children and co-heirs. We may have to suffer persecution or we just have to die to self—his sufferings. But then we will also share in his glory.