Denis,

Original sin is the condition by which mankind, born of Adam and Eve, the first parents, are subjected to a fallen nature, one in need of redemption. Since they fell out of grace with God, they didn't have any grace to hand on to us, thereby they couldn't impart grace even to their offspring.

Their original nature was still in harmony with God's grace at the very least, but following their transgression, became out of harmony. So they handed on a grace-lacking nature to their progeny. That nature was more subject to repeated transgressions (concupiscence) and lacked the perfection whereby we could be admitted to God's Kingdom, for nothing impure can enter Heaven. (Revelation 21:27) It is almost like genetics — if you have bad genes that's all you've got to pass along. We got kind of a raw deal thanks to them.

In my reply, I am trying to show how the nature was changed seeing that many think it is not fair to hold us accountable for our first parent's sin, a road Protestants often go down.

So, all of us, while we may not even have personal sin, (consider babies and those incapable of deliberately sinning), have no means to save ourselves and need Jesus Christ. Even the Blessed Virgin Mary, who had no personal sin, needed her Son to obtain for her the grace unto salvation.

In short, we all need God, or even more exactly, Jesus Christ the Son who makes us free. He can overcome our defective nature and make it perfect again by His sanctifying grace. Of course that requires our cooperation, so He is not going to do any arm twisting.

In the end, original sin is like a handicap — which God will enable us to heal and overcome by grace.

Bob