This is a common misconception. No one can really know for sure, due there being zero evidence, that Santa clause dosent exist, there is no tooth fairy, or that a pink teacup with a dead mouse in it isn't orbiting a nearby sun. But those things are so unbelievably absurd that to assign a probability to them is disingenuous. Therefore anyone with this level of doubt is termed an atheist.In my understanding, if you don't know then you are agnostic.I'm simply a atheist because i acknowledge the fact that I don't know and that nobody actually knows.
You all gotta problem with that? You actually believes i will be tortured for 500 trillion years + eternity?
Who but a sick physcopath wants Christianity or the countless other religons to be true.
Look up the definition of faith.
Of course demised may have a different reason but that is the gist of this typically.