Well that must mean once one is "born-again", he is incapable of ever sinning again, right?
Waiting for her to say that the flesh can sin, but the Spirit can’t. Or, God’s law is only for the unsaved.
Not so. We are all more than capable of sinning even though we are saved. Paul struggled with that and addresses it in Romans 7. As long as we are in this body, the old human nature is with us and yields to that temptation.
We do have to give account for what we did in this life. And there are consequences for sinning. However, sinning does NOT cost us our salvation because we didn't earn it. It's a gift freely given by God to those who accept it.
God does not abandon us or disown us when we slip and fall into sin any more than any human parent disowns his own child for disobeying them. The wayward child is still part of the family. God is always working through His Holy Spirit to convict us of that sin and bring us to a place of repentance and restoration of fellowship with Him. He is not so capricious as to toss us aside for every little sin.