The Most High Power/Authority a.k.a. G-d, HaShem, is, was, and is to come (cf. Hitgallut 1:4,8, 4:8, 11:17). He was not born. He had no beginning.
Yeshua, on the other hand, like Adam, had a beginning. Like the first Adam, Yeshua is called Son of G-d (cf. Luke 1:35, 3:38). Not only the Son of G-d, however, but the Firstborn of All Creation (Colossians 1:15b)—the beginning of G-d’s creation (Hitgallut 3:14). He was therefore in the beginning with the G-d (Yokhannan 1:1). It was for this claim, and not that he is G-d Himself (see Man of Heaven), that he was condemned by the Sanhedrin for blasphemy (Mattityahu 26:63-66, 27:22, Mark 14:61-64, Luke 22:66-71, Yokhannan 5:18, 19:7).
Having conquered death for all through his sinless life, Yeshua is also the Firstborn from the dead, that he might have pre-eminence in all things (Colossians 1:18). By virtue of that sinless life, HaShem appointed Yeshua to the position of Firstborn, highest of the kings of the Earth (Tehillim 89:27); the king of Yisrael, HaShem’s Firstborn nation (Shemot 4:22).
As King Messiah says, ‘I will tell of the decree: HaShem said to me, ‘You are My Son; today I have brought you forth / begotten you. Ask of Me and I will make the nations your heritage and the ends of the Earth your possession’ (Tehillim / Psalms 2:7-8). As HaShem says of King Messiah, ‘He will cry to Me, ‘You are my Father, my G-d, and the Rock of my salvation!’ And I will make him the Firstborn, the highest of the kings of the Earth.” (Tehillim 89:26-27).
Yeshua, therefore, is the Firstborn among many brothers, his disciples who become like him (Romans 8:29, Mattityahu 12:49) and are looking forward to their full adoption as sons at the first resurrection (Romans 8:23). The Children of Adam who put their faith in G-d through His Son, submitting to the Son as Lord, are born again as the Children of G-d through him (Yokhannan 1:12-13, 1 Yokhannan 3:2, 5:1, Romans 8:23). And just as the Firstborn Son of G-d is not the Most High G-d, HaShem, neither are his brothers.
Notice carefully that Yeshua and his first disciples never claim Yeshua is “god the son” as Roman Catholicism and her daughters have erroneously declared. On the contrary, as Yokhannan says, ‘Who is it who overcomes the world except the one who believes Yeshua is the SON OF THE G-D’ (1 Yokhannan 5:5). It should be clear, if not for prevalent error: one who is the son of another is by definition not the other. In this case, the Son of G-d is by definition not the Most High G-d, HaShem.