Some of the new atheists have likened belief in God (I'm thinking especially of the Judeo-Christian-Islamic conception of God) to belief in Zeus, Santa Claus, and other beings that are known, to a fairly high degree, to not exist. There is, however, a major disparity involved in their comparisons. Let's start with the fact that God is supposed to be a transcendent personal creator of the universe. Zeus may be personal, but he's certainly not transcendent. Take the statement:
1. The universe has a transcendent cause.
Is (1) obviously false? Can it even be said with a high degree of certainly that (1) is false? Not at all. Even without the use of argumentation, we can see that (1) provides evidence for the rational acceptability of theism. Contrast (1) with:
1*. There is an embodied god living on the top of Mount Olypmus.
Certainly, there is no explicit contradiction in (1*), but we also have many good reasons to think (*1) is false. For one thing, we have travelled to the top of Mount Olympus and no gods have been discovered. This appears suspect (to say the least) given especially that Zeus is an embodied god. It's not like he is omnipotent or immaterial, the latter two of which would explain why something has not yet been discovered empirically.
Now take the next step:
2. The universe's transcendent cause is a personal agent.
Once again, (2) is not obviously wrong. In fact, there are good reasons to think (2) is true. Just think of the incredible fine-tuning of the universe, the possibility (and later actualization) of entities evolving who possess rational cognitive faculties and knowledge of an objective moral law. These are all data we would expect to find if God exists. If God does not exist, however, the probability of discovering these things, on the hypothesis that God does not exist, is either low or inscrutable.
I conclude that one should abandon atheism/naturalism in favor of some form of theism.