The entirety of scripture has as a major theme, the sincerity of love - to friend and enemy alike. Romans 12:20 (derived from Proverbs 25:22) speaks of "heaping burning coals of fire on his head," an image which seems to connote revenge or malicious getting even. The difficulty seems to reside in a Hebrew idiom which is not clear without a cultural context. The context is hospitality to a stranger- including an enemy, to which we offer food, clothing, and a means to keep warm. If a stranger's fireplace went out in the cold of winter, the noble sacrificial thing to do would be to take embers from our own fire, placing it in a container enabling the stranger to re-ignite his fire, keeping warm. Consequently, heaping coals of fire on his head was not done with a vengeful motive, but for his comfort. Knowing the idiom ensures proper understanding of the meaning. We should not be overcome by evil, but must overcome evil with good.