Jesus is fully man, and fully God - Divine in nature,
Divine -> of or like God or a god:
We know the 2nd Adam Man is "of" God, as per his birth etc Luke. Like God -> God was dwelling in him without measure, doing the works through Jesus John 14:10, Acts 2:22, so naturally he would appear in the form of God. God in a Temple. A god -> We see in John 1:18, after the cross that Jesus is referenced as an only begotten God. (meaning he once wasn't). So claiming a human cannot become a god is false.
God is NOT man and doesn't change. God is one as in a singular being, One Spirit. I and the Father are one, as in one mind etc, no more and no less. (John 17:20 -23).