All of Him stayed behind.Not to argue with you, but are you listing to yourself? you said "all of the Spirit, God was in that flesh, but now you're sayng, "they would not cease to dwell in eternity." but you answered "ALL OF GOD CAME AND WAS IN THAT BODY. the you said, "So then, when the Father descended to incarnate as the Son, He also stayed behind in eternity. And from there He is able to uphold the Universe."
well, how much stayed behind? but don't forget you said "all of him came".
so how much was left behind?
see your dilemma now?
PICJAG
I don't think you are understanding the nature of infinite vs. finite and eternal vs. temporal.
Try to think about how anything that is infinite and eternal can cease to be infinite and eternal; even if the same did condescend to become one of us.
He dwelleth in eternity. He filleth eternity.
If He descended out of eternity, explain to me how He would also cease to dwell in eternity. if He did, He would no longer inhabit eternity...nothing there in eternity anymore. But that is the nature of time; not eternity.
I think that you are failing to understand because your brain simply doesn't go there.