John 5:26 (Berean Literal Bible), “For as the Father has life in Himself, so also He has granted the Son to have life in Himself.”
The miraculous nature of the incarnation of God’s Spirit within the virgin defies all human experience because God Himself has declared, “there is NONE LIKE ME” (Isaiah 46:9). Hence, only our omnipresent Heavenly Father can become a distinct human son with a distinct human self-existence while never having to vacate His omnipresent Self Existence in the heavens. Since angels and men cannot exist in two or more locations at once like our Most High God can, it is hard for us finites to conceive of the idea of God Himself coming into our world as a distinct human being without leaving heaven.
Hebrews 1:3 (KJV), “…who (the son) being the brightness of his glory (the Father’s glory) and the express image (“charakter” = a “copied image”) of his person (“hypostasis” = the “Essence of Being” of the Father’s Person)…”
Hebrews 1:3 clearly states that the Son of God was copied (charakter) from the Essence of Being (hypostasis) of God the Father’s Spirit Being as a true human being with an authentic human “life in himself (John 5:26).” Hence, our God who was “manifested in the flesh” (1 Tim. 3:16) via His own Holy Spirit who came down from heaven (Matthew 1:20; Luke 1:35; John 6:38) also reproduced a human image of His invisible Self Existence (Col.1:15; Heb. 1:3) as a fully complete human self-existence (John 5:26 shows that the Divine “life in himself” also granted a distinct human “life in himself”). Therefore, only our omnipresent Heavenly Father can enter into our world in a new human mode of His existence in order to “save His people from their sins (Matthew 1:23)” while never ceasing to exist as the omnipresent Spirit of God in the heavens (Jer. 23:24).
The new human mode of existence of Emmanuel “God with us” (Matthew 1:23) as a true human son had to have been “made like unto his brethren (Heb. 2:17)” just like all human beings are made or he would not have been a true man at all. If Jesus did not have a true human existence with a distinct human “life in himself” (John 5:26) then he could not have prayed or have had the capacity to have been tempted by the devil. Wherefore, the Son is not God with us as God, he is Emmanuel God with us as a true human being.
Almost all Trinitarian theologians confess that an alleged God the Son remained omnipresent in heaven while he simultaneously became a man. Thus they also affirm that God (in their case a God the Son) became a man. However, that would mean that an alleged God the Son retained a distinct omnipresent Divine “Life in Himself (John 5:26 – God as God)” in the heavens while He simultaneously existing as a distinct human “life in himself (John 5:26 – God as man)” on earth as a man. Such a belief would necessitate two Son Persons: A Heavenly God the Son who retained His Divine Life and Attributes in heaven (who could act and speak as God independently from his new human existence) and a distinct human Son who could act independently on the earth to pray and be tempted. This is essentially the same concept of God the Father’s divine life also becoming a distinct human life in the incarnation through the virgin. While the scriptures plainly speak of the Father’s timeless divine “life in Himself” in heaven and His new human “life in himself” on earth which was “granted” in time (the Son’s new human life harmonizes with Oneness Theology - John 5:26; Psalm 2:7; Heb. 1:5), nowhere can we find a single scripture showing a distinct timeless divine life of a God the Son who would have retained his divine life and attributes in heaven while simultaneously becoming a man. Wherefore, Oneness Theology brings harmony to all of the scriptural data while Trinitarian theology does not!
In conclusion, only our omnipresent God who we know is our “only true God (John 17:3)” the Father can come into this world as a human being while never ceasing to be what He has always been before manifesting Himself in the flesh as a true human being (1 Tim. 3:16; Heb. 2:17). Thus we can affirm that God becoming a man is the exact same thing as God becoming a son. While such a concept defies all human experience, there is nothing which would prevent our miraculous God to also become His own human son in two distinct modes or manifestations of His existence: God as God with a distinct Divine Life in Himself and God as man with a distinct human life in himself.