No reason justifies disbelief.

[Mr.wizard]

What does open minded mean to you ?

Have you found a way to confirm (by any means) if it's reliable or not ?

What does reliable mean to you ?

I'm not sure. This is new to me. 

I guess that open-minded would mean that you agree there may well be reliable things which cannot be confirmed though intersubjective empirical evidence (i.e. science). 

I brought up revelation only as an example of something which isn't available to science. The first reaction was to assert that all revelation is illusion. But that's begging the question. Just because a lot of what people call revelation isn't really, doesn't mean there's not real revelation out there. (I don't believe there is; I'm using this as a way to think about reliability.) 

If I had had a revelation, or knew someone trustworthy who had had one, I would be able to answer the question better. 

So let's say we can't judge whether revelation is reliable or not, because we lack data, and only know of false positives at the moment. If we found a way to judge what is real revelation, it might be reliable. 

An analogy: all telephone messages from your uncle are reliable. But you have 10 fake uncles who call you who are not reliable. In every case, your real uncle is reliable and your fake ones aren't. The trouble there is not whether your uncle is reliable, it's determining which call is really from your uncle. 

And another possibility: inspiration. 

This need not be from an external source. The subconscious is fine as a source which is not available to science. Suppose you're an artist working on a painting that isn't going well. You sleep on it, and in a dream or half-waking state you get exactly the idea you need to fix it. Neither the dream, nor the mental image, nor the judgment of quality concerning the painting, are something that science has access to. Still, I find it reliable. (I'm a painter and I have frequently gotten reliable ideas in this way.)

So there are two possibilities of using the word reliable that aren't scientifically testable. I'd be interested if open-minded people here could think of others.

I don't know how you could say anything about divine revelation, you haven't established that there is a divine being, that a divine being can or wants to reveal things, how revelation works, or that any perceived revelation isn't some sort of a delusion. You have to do a lot of work before you before you can claim that revelation isn't available to science.