I recommend doing some reading in the genre of philosophy of religion. Nietzche will not have the answers you are looking for. He denies all truth, let alone religious truth. If you read the great philosophy of religion authors (Anselm, Augustine, Wittgenstein) you will find that many of them will argue that spirituality is a completely non-rational idea. It cannot be argued for or against, because it is not the object of rationality at all. Instead, spirituality is an entire unique realkm of its own. Religious experiences are usually experienced entirely independent of traditional "senses" and cannot be discussed in terms of these senses. So, argument is useless in these cases. If someone says he had a religious experience or vision, there are no words in human language to properly convey the nature of that experience to you, because it was a non-sensory, or at least beyond sensory, experience. Really interesting stuff.
