I'm going to step in here as a devil's advocate with the position that revelation is indeed evidence. To have a spiritual experience is to bypass the process of gathering bits and pieces of the world which point to a deity, and see that deity directly. By analogy, it's a pointless exercise to use bayesian inference to try and figure out what color ball is in a paper bag based on circumstantial evidence, when you've already gotten a peek inside.

If the concern is verification, well you're hardly in a vacuum - the vast majority (~85%) of the human race believes in religion. While not all of those people came to religion by a revelatory process, it doesn't seem unreasonable that the number who did are in the 100s of millions if not low billions.