Who's the most prominent Christian on this forum?

[Simon Moon]

I don't think it makes much sense to tell someone they should reject a true belief because the belief is unjustified.

Sure, he shouldn't believe that there are giant invisible penguins that crap stars--but that's because such a belief would be false.

If some religion happens on a belief that seems to coincide with some later, evidence based discovery, that does not justify their belief. They obviously had no way of knowing that black holes existed. Why should we, looking back on their belief, think that their belief had anything to do with actual black holes just because they had a vague description?

What if instead of an entire religion, it was just a single paranoid schizophrenic that happened to record his rantings of light and mass swallowing objects, and everyone else at the time thought he was a raving lunatic? Was he just lucky that his rantings happen to seem like a close match to black holes, or did he have some kind of 'special knowledge'?

From the point of view of the religion, they have no way of knowing that the existence of object s that fit their description are any more real than star crapping galactic penguins.

Suppose that the overwhelming majority of evidence available to X indicates that some claim C is true--but that, in fact, C is false. Doesn't it seem contrary to reason to urge X to believe C?

If all we had to go by was the overwhelming majority of the evidence available, yes, it makes sense to urge X to believe C. That's the way knowledge works. Believe that which is best supported by evidence. If it turns out to be wrong, change views, once the evidence warrants it.