Everyone believes things they cannot prove. The question is: How much proof is enough to warrant belief? Consider this fictional conversation between Fred, a reasonable fellow, and generic Mr. Skeptic:

Fred: I have a brother named Jim.
Skeptic: I don’t believe you.
Fred: Ummm … why would I lie?
Skeptic: I don’t know. Maybe you’re crazy. You made the claim. Prove it.
Fred: Well … I have a picture of him in my wallet. Here, look. See it says “Fred & Jim, June 2005? on the back.
Skeptic: That could be anyone. How do I know it’s your brother?
Fred: Okay, here’s one of us together when we were kids. See the resemblance?
Skeptic: Hah! That could be your cousin, not your brother. Or maybe you were just friends. Besides pictures can be edited; I know how to use Photoshop and could make a picture like that in an hour.
Fred: Okay, what if I arranged a meeting, where you could meet him for yourself?
Skeptic: This “Jim” as you call him could just be lying. Or he could be crazy too.
Fred: But we have the same last name! And we look the same!
Skeptic: Could just be coincidence that your last name is the same. Or you could have changed it, it’s easy to change a person’s name. You could have just styled your hair and other features to make yourselves look similar, and/or had plastic surgery.
Fred: Argh!!! Okay what if we had a DNA test done? That would prove it!
Skeptic: Those tests could be faked. What if this “Jim” guy is a scientist? He could fake them himself. Or what if he’s a master forger? Or he could just bribe someone to fake them. There could be a whole conspiracy behind this!
Fred: ….. you’re a dork.

This is a somewhat frivolous example. But it demonstrates that everyone believes things we can’t prove 100% and that we are quite right to do so. What kind of evidence do you require? How much proof is enough to warrant "faith"? Good faith should not be blind, but nor should it be held to unreasonable standards of proof. We should not pass the buck by claiming there is not enough evidence to decide; we all must choose. Make sure you choose correctly!