Jesus carried our sins, not his own.
The sin nature comes through the father, not the mother.
That is why Jesus was born sinless. Not because Mary was sinless, but because He didn’t have a human father.
He had to have a human mother in order to be born in a human body.
That still doesn’t answer the question of why Mary remaining a virgin is so critical. Sex within the confines of marriage is not a sin.
I think you misunderstood my question. A few posts back you said something to the effect that if Mary had been born into original sin then Jesus would have been born into sin.
My question was then, how was Mary not born into sin, where her parents sinless? You said it was a mystery to you.
Then I asked obviously not very clearly :) that if God could mysteriously cause Mary to be born without original sin then why couldn’t God just have allowed Jesus to be mysteriously born without original sin even though Mary was born into original sin.
Wow it is late and I have no idea if my questions are coming across coherently.