That's not exactly what believe means. In a way we can't be sure of anything, including our own existence, so everything we do is believing something based on what evidence we have. The difference between that and a religious conviction is that religion requires you to stop basing your believe on any evidence at all, and believe in their stuff regardless.
If I tell you I ate a piece of bread this morning, you'll believe me. If I tell you I ate a piece of Uranium, you wouldn't. Even though, you have the same amount of evidence for both claims. That's normal believe. Religious believe requires you to believe everything religious higher ups tell you, but because humans aren't wired to do that, they only tell you shit you can't actually check, so your believes are "justified".