The way, the truth, and the life – Jesus Christ, page-1844

"Jesus is the incarnation of God, which means that God became human in the person of Jesus."

I missed a KEY point here = your words here are showing an Anti-Christ.

1 John 4:3 - and every spirit that does not confess that Jesus Christ in flesh come is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world.

(Note there, mans spirit are his words = spirit and words deemed as one and the same, blowing your line of thoughts out the door, that God who is Spirit, cannot be deemed as WORD, showing your lack of understanding of the many meanings and representations of word, words).

The above quote does not mean he was made flesh from something else, as in reduced to flesh, it simply means that his ONLY EVER existence is flesh, the 2nd Adam Man and not some half breed 2nd Adam, as a 2nd Adam is EXACTLY that.

The only difference apart from God having greater plans for him and created for him is, Jesus was made by the word (Eph 3:9) and power of God which came down, no more and no less came down, that is why pre the cross, we never see Jesus say, I go BACK to the Father, as he never previously existed.
Because the word and power came down from heaven, the 2nd Adam is heavenly = not made of dust like the 1sr Adam.