"It's a set of beliefs that a person holds to be the truth, without proof."
Wrong. Church goers believe there is proof. Atheists certainly belive there is proof.
As for religon being vital to humanity, maybe it is, but only because people are afraid, weather they are afraid of death, or damnation. It's completely based on fear, and that is pathetic. It's far easier to "give in" and belive in a god, and a heaven, and eternal after life, than to embrace the idea that there is nothing after death. (My ex Christian girlfriend even admited this, naturally I was blown away.)
I've been an atheist since I can remember. ^_^