My parents come from different religious backgrounds, my father was raised as a Lutheran while my mother as a Kardecist. Neither cared a lot about their religions, so while they tried to give me the general notions of their religions I was free to make my own mind.
So, having no pressure to follow my parents beliefs, and founding no logic reason or need for the existence of a God, I found myself an Atheist.
I can't believe on it because I can't find any logical reason to do so.
Also, knowing how much evil was done in the name of religion I came to have a strong opinion against the notion of faith. I really think religious faith, that is, believing without proof, is a disease that must be eradicated. No good that came from it justifies all the bad things that came along.