A problem for those that argue for the divinity of Jesus is that he was born of woman, and came into existence. The obvious problem with this is that God is eternal, he always was, and was never born or coming into existence. To solve this problem Trinitarians came up with the idea that Jesus always existed, even before he was formed in the womb of his mother he is already in existence.

So let us turn our attention to the Book of Hebrews, a book in the New Testament, let us go specifically to chapter one to see what the author said concerning Jesus:

In the past God spoke to our forefathers through the prophets at many times and in various ways, but in these last days he has spoken to us by his Son (Hebrews 1:1-2)

The above verse is another great refutation to the argument that Jesus was always in existence and eternal. As the verse says, God has spoken to people in the past through several means, including prophets, and now in the last days he has spoken to us through his Son, namely Jesus. Therefore this means that God has only begun to use Jesus during the last days, and Jesus wasn't being used before in the past, surely if Jesus existed eternally, and acted as an agent during the Old Testament times (as the Angel of the Lord as some Trinitarians contend), then the author of Hebrews would have mentioned it, yet the author of Hebrews makes it clear that Jesus was not an agent of God until the LAST DAYS, basically the present day of the book of Hebrews.

Christian Unitarians (Christians who don’t believe in the Trinity, or the divinity of Jesus) also noticed the implication of these verses from the book of Hebrews, writing: 

A text which surveys God's activity over the ages says, "God spoke long ago to the fathers through prophets in many portions and in many ways, but [in contrast] in these last days has spoken to us in His Son" (Heb. 1:1-20). This would seem to confirm that until his human birth Jesus was not Son of God nor God's messenger to man. This same book of Hebrews points out that the Word was spoken through angels in the Old Testament times (Heb. 2:2). If the message to Israel was through the same preexistent Jesus who became man, the writer of this New Testament book seems to lack any such information. Messages were given through prophets and angels certainly, but never was there a hint that the Old Testament message was transmitted through the one who later came to be identified as the Son. (Anthony F, Buzzard, Charles F, Hunting. The Doctrine of the Trinity, Christianity's Self-Inflicted Wound. International Scholars Publications, 1998. PP. 108)

Another New Testament book that refutes the supposed preexistence of Jesus comes from Colossians, which says:

He is the image of the invisible God, the firstborn over all creation (Colossians 1:15)

According to Paul Jesus is the firstborn of creation. This means that Jesus is therefore part of creation, and isn't preexistent. If Jesus is the first born of creation, then how is he eternal? An eternal person is not the first born of anything, because he always was, and always existed. But if you’re the first one out of creation, or the first born of creation, this surely means you’re obviously not eternal, you’re simply the first born of creation.

Another obvious problem for Jesus’ supposed eternal existence, is not that he was simply born of a woman and came into being and existence, it’s that he also died. Now as well know, if one is eternal, then the concept of death is impossible for them, for if one dies, that that person is obviously not eternal because. Yet the Gospels clearly teach that Jesus died, he was killed, so the fact that he was killed, proves he is not eternal, unless Trinitarians want to actually make the claim that God died, which that in itself, is an oxymoron.

God is eternal, he is the ever living, and as such, he cannot die, he will not die, and he will never die, if God dies then he isn’t God. It’s like saying God can’t lift a stone.

, [27.10.20 01:02]
That’s an impossibility because God is all powerful.and so if mething contradicts his attribute, then he can’t be God, in other words it’s impossible for God to have his attributes contradicted or diminished, it’s simply not possible, for it were possible, and it did happened, he wouldn’t be God because he’d now be imperfect and in contradiction with his own perfect attributes.

So if Jesus died, he can’t be God, and he sure can’t be eternal, because God is eternal, and God never dies. You can’t have one or the other, this is an absolute concept, there’s no two ways about it.