RefBap
I really don't have anything more to add to what has already been stated.
But to put it all in a nutshell, I would say that RCs believe that it is both the work of God & the work of man that saves. Where as the Bible says that only God saves by grace through faith and as a natural out flow of that salvation, comes works. If no works flow, then obviously we should question if salvation has occurred.
As James 2:18 says "...:shew me thy faith without thy works, and I will shew thee my faith by my works."

Tom