One evening, an elderly Cherokee Brave told his grandson about a battle that goes on inside people.
He said, "My son that battle between two wolves is inside us all.
One is evil. It is anger, envy, jealousy, sorrow, regret, greed, arrogance, self-pity, greed, resentment, inferiority, lies, false pride, superiority, greed and ego.
The other is good. It is joy, peace, love, hope, serenity, humility, kindness, benevolence, empathy, generosity, truth, compassion and faith."
The grandson thought about it for a minute and then asked his grandfather, "Which wolf wins?"
The old Cherokee simply replied, "The one that you feed." Source