The attributes of werewolves are substantially different than the ones ascribed to the Jewish-Muslim-Christian God. Werewolves are believed (by some people, sure) to exist within our time-space continuum, to respect the same laws of physics we do and to pretty much be more or less a very strong mammal that is sensitive to the calendar as well as to moonlight. Those believers have created testable hypothesis that were proven wrong many times. I say the werewolf question is quite settled.

The JMC God exists outside our space-time continuum, since before the Universe and is said to have caused its formation and to interact with it in some way or the other, sometimes violating causality. Good luck trying to shape that into a testable hypothesis ;-) I won't bother with it until someone cooks up a decent one.

So, as only a true agnostic can say, I don't care if God exists or not. It's not a question I can answer.