You are great at telling me what I believe and mean and taking Scripture out of context. Why did you start with vs. 16? Is it because vs. 15 weakens your argument and when we understand vs. 15 this Trinity proof no longer proves the Trinity?
Colossians 1:15
15 Who is the image of the invisible God, the firstborn of every creature: KJV
In this verse the Greek translated "firstborn" is "proototokos", which indicates preeminence not preexistence. In the Septuagint Ephraim is referred to the Joseph's "proototokos" although Manasseh was Joseph's "firstborn". Jesus was greater than Adam in God predeterminded plan, Jesus did not exist before Adam. Also we have already covered the meaning of "descended from above" and "descended from heaven" on the thread you started.
There is no Scripture in either the OT or the NT that plainly states that Jesus preexisted as a divine entity and a mass of Scriptures that tell us Jesus was and still is a Man. The only way you can view Jesus as preexisting is to intepret various Scriptures to teach this and appeal to tradition. Now, even if you can establish Jesus' spirit existed in the beginning Colosssians 1:15 can be interpreted to mean His spirit was born, which defeats that Jesus is God since God was not born.
When we take the time to study the meaning of Koine Greeks words and the idioms used by the Hebrews your proof texts are exposed as interpretations that contradict God's truth.
The Greeks of this period believed Jesus was preexistent, because, Aineo, it is supported in scripture. Almost every single Christian group, even heresies, maintain that belief. Jesus is God as a Son of Man, so is the image of the invisible God. That's a much straightforward interpretation.
Verse 15 correlates with verse 18, stating that Jesus was the firstborn from the dead that He may again be preeminent, and return to His place of Godly Glory. Jesus was preeminent in the Beginning when He created all things.
What can you say about verses 16 and 17? Quite another story, right? This appears to be about Jesus's preexistence rather than preeminence.
The Transfiguration is another example of Jesus transforming into a state of His preexistent Glory.