Proverbs 25:21-22
21 If thine enemy be hungry, give him bread to eat; and if he be thirsty, give him water to drink:
22
For thou shalt heap coals of fire upon his head, and the LORD shall reward thee.
Man, I love this verse! Here God teaches us how to be devious towards our enemies, and how to lour them into a false sense of security. I often employ this method on visiting Jehovas Witnesses.
Invite them into your home ... make them feel comfortable ... ask if they would like something to eat ... seat them in a nice comfy chair. Then, when their guard is down, rain hot burning coals upon their heads! They never see it coming! Glory!
It's verses like this one that make me glad I'm a Christian! Hallelujah!