...many people argue for (their) god by pointing out that they are often "feeling his presence" and since many claim to speak with him as well, maybe that's really just one form of tupla without the insight that it is actually a hallucination.

Surely that's not how most people experience belief, but I never really considered that some of them might actually carry around a vivid invisible (or visible for all I know) hallucination quite like that. Could explain why some of the really batshit crazy ones going on about how god constantly speaks to them manage to be quite so convincing.

From now on my two tulpa buddies will be Eliezer and an artificial intelligence engaged in constant conversation while I make toast, love, and take a shower. Too bad they'll never be smarter than me though.