One day, God is going through his records and realizes that Mother Theresa was accidentally sent to Hell. So he calls up Satan and says, "There's been a mix-up. You've got Mother Teresa down there."
Satan says, "Yeah, I know, it's great. She's re-decorated the place, she's always bright and sunny, and she even helps out every now and then. I'm keeping her."
God says, "You can't do that. You send her back up to Heaven or I'll sue you."
Satan says, "Fat chance. I've got all the lawyers."