Many atheists start as believers in some kind of religious doctrine but eventually come out of it. I'm one of those. I was raised by my devout grandmother and my abusive, alcoholic mother. Grandma told me that if my faith was deep enough, prayer would see me through any crisis. So I attended the local United Methodist church, went to the youth group meetings and attended Boy Scouts in the church's basement. I even learned to bake so I could contribute to the church's coffers (we were too destitute to tithe much).
My life was pretty awful and no matter how much I prayed, it never got better. But God was perfect so the defect must have been in me and with my faith. This further damaged my already shaky adolescent self-esteem. Grandma kept right on telling me to have faith and keep praying. School was a nightmare and home, when my mother or sister were there, was worse.
Finally, in a fit of desperation, I figured that I'd either get an answer or God would strike me dead. I went out in a terrible lightning storm and challenged God (remember that I was a young teenager). It was a little like the line from Cool Hand Luke, "Come on. Love me, hate me, kill me, anything. Just let me know it." I don't recall the actual challenge but I remember just getting wet, coming down from the roof and telling my grandmother, "Yeah, that's what I thought."
I also discovered the only reason we were Methodists is because the other church we might have attended was three blocks away instead of only one block away. It was an accident of geography. If we'd lived on Fourth Street instead of Second Street, we'd have belonged to the Church of the Brethren.
For years, I tried to figure out where I belonged as far as faith went. I wasn't even aware of the idea of atheism until I was 21. I was walking along a college campus and found a scrap of paper that had quotes from Thomas Edison, Clarence Darrow, Ben Franklin, Thomas Jefferson and other free thinkers. And suddenly, it all became clear to me. God hadn't answered a single one of my prayers because I was talking to no one. Finally, it all made sense. No gods, no heavens and no hells... how much simpler could it be?
I still has issues to deal with but came to the realization that the only person who was obligated to watch out for me was me. I had a lot of work to do. I went back to college and discovered a long lost passion for science, especially astronomy.
Today, I'm reasonably well adjusted. I still have to deal with the day to day issues that effect everyone (work, entertainment, money, etc.) but I now have the tools to deal with them in a realistic and rational manner. I've been married nearly 20 years and have two great kids. I'm teaching astronomy for a living and love doing it despite the occasional religious whack-a-loon who asks me why I don't include creationism.
Last year, I went to my 30th class reunion and everyone commented on how much I'd changed since high school. One of the women said that she didn't remember that I'd been so funny or laughed so much. Another said, "You seem so much more confident and comfortable with who you are." She got a kiss!
Religious folks often speak of how much better their lives became when they found God but the opposite was true with me. Getting rid of God was like getting rid of a cancer but instead of withering the body, this disease was withering my mind. I didn't lose faith; I found reason.
It's a lot better life.