One might think that the following marks a significant difference between religious and sensory experiences:
- If x in context C has a veridical sensory experience of K, then typically another person in C with properly functioning sensory apparatus would also experience K.
But (1) is false. Here is an easy counterexample. There are some things that are "on the edge" of normal human visual capabilities. For instance, seeing a paramecium or the Pinwheel Galaxy (in a dark enough sky) naked-eye is like that. If the organism were somewhat smaller or the galaxy somewhat fainter, people with normal vision would no longer be able to see it. But people with exceptional or well-trained vision (with "vision" understood broadly as including the brain post-processing of noisy data) still could. Thus there will be cases where a person has a veridical sensory experience of a tiny organism or a faint galaxy, but it is false that typically another person with properly functioning sensory apparatus would also see it. Only a person with exceptionally well functioning sensory apparatus would see it. Moreover, even such a person might not be able to see it under all conditions, but only under conditions of being optimally concentrated and rested.
Perhaps we can save (1) by replacing "properly functioning" with "properly functioning on this occasion at least as well as x's faculties in C were". Call this "(1*)". But now it is harder to tell that the analogue to (1*) is false in religious experience cases. For how would we compare how well different people's religious experience faculties are functioning on different occasions. So while it may be that the analogue to (1*) is false in religious experience cases, it is hard to give a non-theological argument for this. (One can give a theological argument by noting that God is surely free in choosing to whom he should reveal himself.)
Moreover, it seems that it can be a matter of chance what one sees and when. Last night, I was looking at NGC 6852 through my Coulter 13.1". Very faint, i.e., low contrast, even through an Oxygen III filter (it wouldn't have been so faint in a darker sky, but my backyard has a lot of light pollution). First, I just saw the blackness of the sky. Then eventually my eyes (or brain!) picked out a very, very faintly brighter patch of the darkness. Then that disappeared. It reappeared again. Eventually I managed to "hold it in view" for a longer time. A fuzzy elliptical patch of extremely faint light. It seems that I was dealing with a pretty random process of perception here: sometimes my brain was managing to pick the nebula out of the visual system noise and sometimes it wasn't. There may have been some oscillation in the atmosphere, but it probably wasn't relevant (it's relevant to seeing detail, but not so much to seeing a faint object).
Now, it is possible to put all this detail into the context C. But then one is in effect building into the context that the situation was such that one would manage to experience K. And that trivializes (1*) and makes it impossible to point out a difference with religious experience.
One might try to save (1) in a different way. Not by saying that the particular experiences—say, of that faint nebula—would be had by someone else, but by saying that anybody with properly functioning faculties at some point have some experience of this sort (say, a visual experience). But now it is not clear that religious experiences fail to pass muster. After all, a lot of people have religious-type experiences, say while seeing a sunset or a really elegant proof of the Pythagorean Theorem. And while some don't, it is far from obvious that this isn't just evidence that their sensus divinitatis is malfunctioning.
However, I think there is theological reason to think that this needn't just be a malfunction (e.g., think of the phenomenon of the dark night of the soul). So there is theological reason to think that religious experience is disanalogous in this way from sensory experience.