If a god descended from the heavens and spoke to you, personally, declaring existence and providing myriad demonstrations of divine power, I expect you would reconsider your belief at least a little bit.

Given what you already know about the world (including the possibility of insanity and simulations), how much evidence should be necessary to convince you in that situation? A subjective year? One hundred? One thousand? More? Once you've already decided that you're insane or in a simulation with probability X, I can't see how any evidence of anything would be useful if you already assign less than probability X to that thing. It's a local minima you can't escape from as far as I can see. One reason I'm not especially anti-religion is that I think that at least some theists are in the same position: there's no evidence that is more likely to be real evidence that there is no god than it is to be evidence of testing by fallen angels, or whatever.

But maybe I've just missed the excellent discussion about this?