Oneness is Antichrist by Definition

https://www.youtube.com/watch?v=hRMATkzUYTA&t=6s
Take note from this sampling of scripture that Jesus is a person (an ‘I’) other than the Father who existed with the Father prior to his coming in the flesh.
Jn.8:17-9 It is also written in your law, that the testimony of two men is true. I am one that bear witness of myself, and the Father that sent me beareth witness of me. Then said they unto him, Where is thy Father? Jesus answered, Ye neither know me, nor my Father: if ye had known me, ye should have known my Father also.
Jn.8:42 Jesus said unto them, If God were your Father, ye would love me: for I proceeded forth and came from God; neither came I of myself, but he sent me.
Jn.16:28 I came forth from the Father, and am come into the world: again, I leave the world, and go to the Father. 17:8 ... I came out from thee

Jn.6: 62 What and if ye shall see the Son of man ascend up where he was before? 1 Cor.15:47 The first man is of the earth, earthy; the second man is the Lord from heaven.
Jn.8:23 ... I am from above: ye are of this world; I am not of this world.
Jn.5:17 But Jesus answered them, My Father worketh hitherto, and I work.
Lk.24:49 And, behold, I send the promise of my Father upon you
Jn.10:15 As the Father knoweth me, even so know I the Father v30 I and my Father are one
Jn.20:17 Jesus saith unto her, Touch me not; for I am not yet ascended to my Father: but go to my brethren, and say unto them, I ascend unto my Father, and your Father; and to my God, and your God.
Jn.14:28 I go unto the Father: for my Father is greater than I. 15:24 both me and my Father.
Rev.3:21 To him that overcometh will I grant to sit with me in my throne, even as I also overcame, and am set down with my Father in his throne.

This might sound strange if you listen the Oneness teachers as they seem to think they alone have the revelation that Jesus is the I AM of the Old Testament.(Ex.3:14, Jn.8:58) But as unitarians (God is unipersonal) as opposed to trinitarians (God is tripersonal) they are forced to conclude a 2nd human person called Jesus was just a man who prior to his incarnation was not a person at all; and who will cease to exist in the future. All you need to do is listen to them explain the passages above or John 17:5 where you have two persons clearly indicated and they will tell you one did not preexist his human birth.

The consistent theme with Oneness obfuscation is when Jesus and the Father are ever speaking to each other or Jesus is praying suddenly instead of 2 persons we have 'flesh' praying to God. Which is supposed to hide the heresy. Suddenly 2 persons become 'human nature' praying to Spirit but only one person. So, if Jesus is not a person there, only 'human nature' then he was not fully a man/person (i.e. Jesus Christ did not come in the flesh). But if he was fully a man/person (i.e. Jesus Christ is come in the flesh) then he was a person with the Father before the world was. Either way Oneness are denying Jesus Christ came in the flesh. And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent. Jn.17:3

It is antichrist to deny that Jesus Christ is come in the flesh (1 Jn.4:1-4, 2:22-3). But they make it meaningless because although in reality the person who was with the Father (Jn.1:1-3, 1 Jn.1:1-3) in the beginning became a man- i.e. came in the flesh. They say the 2nd person (in Jn.17 & elsewhere) was a created person- like every other person and did not preexist. So, he didn't "come in the flesh”, he was just simply a human. In that sense every human being “came in the flesh”. Which means they deny Jesus Christ is come in the flesh- because he didn't previously exist his birth as a person. So, while they are forced to believe in 2 persons, they therefore must insist one was a created man and the other was the Creator.