The appeal of multiple universes—perhaps even an infinity of universes—is that when there are billions and billions of possibilities, then even very unlikely outcomes are going to be realized somewhere. Consequently if there was an infinite number of universes, something like our universe is certain to appear at some point. What at first glance seems like incredible coincidence can be explained as the result of a mathematical inevitability.So if there's no God, then there has to be an infinite number of universes. If there is an infinite number of universes, then pretty much anything that CAN happen will happen. Therefore, if it's possible for a God to exist, he probably does.