Well one argument I take for being atheist/agnostic is the question:
Do we worship (the Christian) God for being right or do we worship him because he holds the keys to heaven?
If God decreed murder was good and murder pleased him, would we do it even though it wasn't morally sound to us? Thus it seems that if your morals disagree with God's you will go to hell. But, since we don't know what pleases some sort of ultimate purpose, we each create what is moral to us, so we can recieve some sort of ultimate reward.
To quote George Carlin:
"God loves you. If you don't do what he says, he'll let you burn in hell for eternity. Yup. He loves each and every one of you."