I Know It But I Can't Prove It, Really

Over at Joanne Jacobs, a commenter (the first one) claims:

In this forum, I once said that one of the two dumbest lines in detective stories is "I know he's guilty but I can't prove it." If you can't prove it you don't know he's guilty, you only suspect it. (There is at least one special case exception: if the proof depends on knowing you are telling the truth.)

Well, I don't know what exactly is meant by the "one special case" mentioned, but there's one very special case that wasn't mentioned, probably because it undermines the commenter's claim: Goedel's incompleteness theorem.

In short, one thing Goedel proved is that there are propositions that can be known but not proved.

Then the commenter goes on to say:

religion teaches making real-world decisions based on feeling and faith even if it means ignoring strong evidence. Christianity is harmless when confined to Sunday mornings. Base your schooling on it, and you have a disaster.

Two things. (1) This comment betrays a woefully inadequate account of what Christians have historically meant by "faith." (2) If you base your schooling on Christianity, what you get is not a disaster but the university.