We try to align our beliefs with reality as much as we can. That may mean holding off on believing something until it can be sufficiently demonstrated. If questioned on these things, we'll typically say, "I don't know"

  • We see in reality that there are planets, so we believe there are planets.
  • We see in reality that evolution happens, so we believe evolution happens.
  • We haven't been given sufficient evidence of an afterlife, so we do not believe in an afterlife.

What we want, or what we think should happen, does not dictate reality. For instance, heaven sounds like a nice place to go, however, since no evidence exists to support its existence, we do not accept the claim that exists.

The word "belief" receives a lot of friction from many atheists, because some usages of the word have religious connotations. On this site, "belief" just means "accepting a claim as true". One can believe something for good or bad reasons.