When it comes to the question of “sanctification” (i.e., growth in holiness, Christ-likeness, and godliness), I frequently pose my students this question:
Are we sinners saved by grace, or, saints who sometimes sin?
On the former, it anchors our identity in our fallen nature and Adamic heritage, so that we are by nature sinners who have been grafted into Christ. The problem I have with that view is that it reduces us to a kind of worm that has been let off the hook. But despite the continued struggle with sin and resisting the world, the flesh, and the devil, something really has changed for believers. They are no longer who they were. They are dead and crucified with Christ. They live on only by a quickening by the Spirit and sharing in the Son. That’s why I prefer to say that Christians are “saints who sometimes sin.”
Any way, Robert Saucy had a good article on this that C. Michael Patton has helpfully reproduced.