Christian Struggle With Sin, but They Don't Live in Sin

Christian struggle with sin, but they don't live in sin. So what is the difference? And I agree that you cannot be in a state of grace with God if you have committed mortal sin and especially if you persist in mortal sin. That to me is a much more dangerous place for a professing Christian to be than just simply a Christian who's struggling with sin. But there are sins that are grave matter based on the, the circumstance and the object of the act and other things like that.