Quote about Prayer by C.S. Lewis: "I pray because I can't help myself. I pray because I'm helpless. I pray because the need flows out of me all the time, waking and sleeping. It does not change God, it changes me.
"To be a Christian means to forgive the inexcusable because God has forgiven the inexcusable in you. Lewis (from "On Forgiveness", The Weight of Glory. Lewis, you are so very wise, and this is something I have such a hard time with.