That's the problem, I don't see anything in scripture to support the premise that the preincarnate Christ was anybody's son and certainly not the Father's firstborn son. You misunderstand Paul's statement in Colossians 1:15.
That's why I asked if you were intentionally being deceptive in quoting Paul's statement.
Paul's premise is true but yours isn't. Why do you promote it?
Col 1:15
Who is the image of the invisible God, the firstborn of every creature:
Col 1:16
For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him:
Col 1:17
And he is before all things, and by him all things consist.
Heb 1:2 Hath in these last days spoken unto us
by his Son, whom he hath appointed heir of all things, by whom also he made the worlds;
Heb 1:3
Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high;
The Spirit son is firstborn of all creation.
Php 2:5 Let this mind be in you, which was also in
Christ Jesus:
Php 2:6 Who,
being in the form of God, thought it not robbery to be equal with God:
Php 2:7 But made himself of no reputation,
and took upon him the form of a servant, and was made in the likeness of men:
Php 2:8 And being found in fashion as a man, he humbled himself,
and became obedient unto death, even the death of the cross.
Php 2:9 Wherefore God also hath highly exalted him, and given him a name which is above every name:
Note that Christ needed to change his form to become flesh in Jesus, Jesus is the body mentioned in Heb 10:5.
Heb 10:5 Wherefore when he cometh into the world, he saith, Sacrifice and offering thou wouldest not,
but a body hast thou prepared me:
The spirit son became one with the flesh son. Both are from God but they became one. Only the spirit son was SENT from heaven, only the spirit son has seen the Father.