Story from Native American Tradition:
An elder Cherokee was teaching his grandchildren about life. He said to them, “A fight is going on inside me. It is a terrible fight between two wolves. One wolf represents anger, greed, hatred, envy, fear, arrogance, resentment, self-pity, guilt, lies and ego. The other stands for peace, love, patience, joy, compassion, generosity, humility, kindness, friendship, truth, and faith. This same fight is going on inside you, and inside every other person, as well.” The children thought about this for a while and then one child asked, “Which wolf will win?” The wise elder replied simply, “The one you feed.”
Taken from “Patience: The Art of Peaceful Living”