William Rowe and others argue that if ours is a possible world than which there is a better, it follows that God does not exist. If this is correct, then if there is no best possible world, it is not so much as possible that God exist. I reject the key premise of Rowe's argument. The key to seeing that it is false, I suggest, is seeing that God is subject to something fairly called moral luck. In this first part of the article, I set up Rowe's argument, indicate my strategy, introduce the notion of moral luck and show how it bears on Rowe's claims.