It is the supreme art of the devil that he can make the law out of the gospel. If I can hold on to the distinction between law and gospel, I can say to him any and every time that he should kiss my backside. Even if I sinned I would say, ‘Should I deny the gospel on this account?’ … Once I debate about what I have done and left undone, I am finished. But if I reply on the basis of the gospel, ‘The forgiveness of sins covers it all,’ I have won.- Martin Luther, via OFI
This was too good to pass up. "Kiss my backside" + "if I reply on the basis of the gospel" = Martin Luther gold.