Jesus was already ‘spirit’.
HE took on human flesh in Mary’s womb.
Did that flesh have the taint of OS?
I do not think the answer is found in Scripture.
However; if it is; I’m sure someone will post the relevant verses.
If Jesus had original sin - would he have been the unblemished lamb sacrificed for us? Also - he was chosen before the Creation happened, but revealed now. I think that sentence implies (states?) that He does not have original sin.
I also don’t think we need to (or even can) FULLY understand God or Jesus to be saved. I had hoped that when I die all of these questions will be instantly answered. I’ve heard a few pastors talk about how heaven will be filled with a lot of praising God, learning, working, etc. So maybe not!
1 Peter: 13-23
Therefore, with minds that are alert and fully sober, set your hope on the grace to be brought to you when Jesus Christ is revealed at his coming. As obedient children, do not conform to the evil desires you had when you lived in ignorance. But just as he who called you is holy, so be holy in all you do; for it is written: “Be holy, because I am holy.”
Since you call on a Father who judges each person’s work impartially, live out your time as foreigners here in reverent fear. For you know that it was not with perishable things such as silver or gold that you were redeemed from the empty way of life handed down to you from your ancestors, but with the precious blood of Christ, a lamb without blemish or defect. He was chosen before the creation of the world, but was revealed in these last times for your sake. Through him you believe in God, who raised him from the dead and glorified him, and so your faith and hope are in God.
Now that you have purified yourselves by obeying the truth so that you have sincere love for each other, love one another deeply, from the heart. For you have been born again, not of perishable seed, but of imperishable, through the living and enduring word of God.