The problem with the Unitarian position is that it attempts to create a special meta-narrative by which it then makes special pleadings for verses that are troublesome. Thus, any "theory" about the nature of God must be jealously guarded against this very human problem. The Trinity and Arianism are NOT immune to this.
The difficulty with Unitarianism is the very large number of special pleadings that it creates because there is so much evidence of Christ's actual pre-existence. It is agreed that some of it could be construed to mean purely cognitive metaphysical existence (ie, not actual existence, but only in the Mind of God, 1 Peter 1;20, - but not many!), but that very assertion flies in the face of much other evidence about Jesus actually being with (not in) God and seeing God, such as:
- John 1:1-3 - In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through Him all things were made, and without Him nothing was made that has been made.
- John 1:14 - The Word became flesh and made His dwelling among us. We have seen His glory, the glory of the one and only Son from the Father, full of grace and truth.
- John 1:15 - John testified concerning Him. He cried out, saying, “This is He of whom I said, ‘He who comes after me has surpassed me because He was before me.’ ”
- John 1:18 - No one has ever seen God, but the one and only Son, who is Himself God and is at the Father’s side, has made Him known.
- John 3:13 - No one has ascended into heaven except the One who descended from heaven—the Son of Man.
- John 3:16, 17 - For God so loved the world that He gave His one and only Son, that everyone who believes in Him shall not perish but have eternal life. For God did not send His Son into the world to condemn the world, but to save the world through Him. [NOTE - God cannot send someone who does not exist!]
- John 3:31 - The One [= Jesus] who comes from above is above all. The one who is from the earth belongs to the earth and speaks as one from the earth. The One who comes from heaven is above all.
- John 6:38 - For I have come down from heaven, not to do My own will, but to do the will of Him who sent Me.
- John 8:58 - “Truly, truly, I tell you,” Jesus declared, “before Abraham was [born], I am!"
- John 13:1, 3 - It was now just before the Passover Feast, and Jesus knew that His hour had come to leave this world and return to the Father. Having loved His own who were in the world, He loved them to the very end. ... Jesus knew that the Father had delivered all things into His hands, and that He had come from God and was returning to God.
- John 16:27, 28 - for the Father himself loves you, because you have loved me and have believed that I came from God. I came from the Father and have come into the world, and now I am leaving the world and going to the Father.”
- John 17:5 - And now, Father, glorify Me in Your presence with the glory I had with You before the world existed. See also V24.
The same idea is taught in other places as well.
- Phil 2:5-8 - Let this mind be in you which was also in Christ Jesus: Who, existing in the form of God, did not consider equality with God something to be grasped, but emptied Himself, taking the form of a servant, being made in human likeness. And being found in appearance as a man, He humbled Himself and became obedient to death— even death on a cross.
- Col 1:16, 17 - For in Him all things were created, things in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities. All things were created through Him and for Him. He is before all things, and in Him all things hold together.
- Heb 1:2, 3 - But in these last days He has spoken to us by His Son, whom He appointed heir of all things, and through whom He made the universe. The Son is the radiance of God’s glory and the exact representation of His nature, upholding all things by His powerful word. After He had provided purification for sins, He sat down at the right hand of the Majesty on high.
Jesus could not create the universe if He did not exist.
In places John 16 & 13 above, whatever is said about Jesus coming from the Father MUST also be said about Jesus going to the Father. Thus, IF Jesus was only in the mind of the Father before the incarnation, then when Jesus returns to the Father, again, He will not physically exist but be only in the mind of the Father.
Then there is the problem that "no one has ever seen God" (John 1:18, 6:46, 1 John 4:12), yet we have numerous places where people see and talk with YHWH such as:
- Gen 18:1, 10 - Then the LORD appeared to Abraham by the Oaks of Mamre in the heat of the day, while he was sitting at the entrance of his tent. ... Then the LORD said, “I will surely return to you at this time next year, and your wife Sarah will have a son!”
- Gen 32:30 - So Jacob called the place Peniel, saying, "It is because I saw God face to face, and yet my life was spared."
- Ex 3:5, 6 - “Do not come any closer,” God said. “Take off your sandals, for the place where you are standing is holy ground.” Then He said, “I am the God of your father, the God of Abraham, the God of Isaac, and the God of Jacob.”
- Josh 5:13 - 6:2 - And the LORD said to Joshua, “Behold, I have delivered Jericho into your hand, along with its king and its mighty men of valor. (V2)
- Judges 6:14 - The LORD turned to him and said, “Go in the strength you have and save Israel from the hand of Midian. Am I not sending you?” [See also V16]
- Eze 1 - the prophet's vision of God; many elements of which are repeated in Rev 4 & 5.
- See also instances of the “Angel of the LORD” clearly being the LORD - Gen 16:7-13, 22:11-17, 32:24-30, 48:16, Ex 3:2-6, 32:34, Num 22:22-35, Josh 5:13-15, Judg 2:1-4, 6:11-23, 13:3-23, Isa 63:9, Dan 3:25, 28, Hos 12:4, 5, Zech 3:1-7, Mal 3:1, Rev 8:3-5, 10:1-10, 18:1, 20:1-4.
- A closely related phrase, “Angel of God” who is clearly God as in Gen 6:13, 8:15, 9:8, 17, 15:13, 17:3, 4, 21:12, 16-21, 35:1, 10, Ex 4:3-8, 6:2, 23:20, 21, Deut 1:6, 1 Kings 12:22, etc. See also Acts 10:3, 4, Gal 4:14.
The very fact that the NT so confidently asserts that no human has seen God the Father, but many people have seen God/YHWH in the OT means the inescapable conclusion is such epiphanies were of the pre-incarnate Jesus as per John 8:58 – “Truly, truly, I tell you,” Jesus declared, “before Abraham was born, I am!”
Thus, there appears to be a difference between Jesus being in God's actual presence from eternity and God's foreknowledge about our existence as discussed in 2 Tim 1:9, Eph 1:4. Further, if Jesus had no pre-incarnate actual existence, then the "kenosis" of Phil 2:5, 6 has no meaning either.