"Do you believe in a god?" If I wanted to, how could I choose one of them? I should just go for one that fits the bill (in this particular case, my needs), but that would be only the fruit of my imagination, an "occasional" god, that answers my questions, that makes my life easy and meaningful. I cannot lie to myself: there's no such thing in the entire Universe (and out of it) and, most important, there's no such thing before the Universe, as that would imply something that created it, a second god, and so on. There's no answer to the initial question, as the self-same question is pointless: if there are more gods, no-one of them can be choosen. If there is only one, we can't know.