God wastes nothing - not even sin. The soul that has struggled and come through is enriched by it's experiences, and Grace does not merely blot out the evil past but in the most literal sense "makes it good."
Dorothy L. SayersPhilip wasn't the sort of man to make a friend of a woman. He wanted devotion. I gave him that. I did, you know. But I couldn't stand being made a fool of. I couldn;t stand being put on probation, like an office-boy, to see if I was good enough to be condescended to. I quite thought he was honest when he said he didn't believe in marriage -- and then it turned out that it was a test, to see whether my devotion was abject enough. Well, it wasn't. I didn't like having matrimony offered as a bad-conduct prize.
Dorothy L. Sayers