Grew up Catholic, was really into the church and prayer and all that. Felt like God "spoke" to me when I prayed (more like a feeling of guidance, comfort, and love than an actual voice). After getting a rough shock when these prayers stopped turning out like I had been "told" they would, I realized every time I prayed for guidance or help the answer I received was coincidentally what I hoped it would be. I figured out that I had basically been listening to myself the entire time.

I didn't lose my belief right then and there - I started asking questions. To friends, to family, to religious leaders. The answers I received were frequently full of reassurance and devoid of substance - and some were just shy of threats ("How dare you question God?"). So I began to research, and the more I discovered about my religion the more I realized how deeply flawed much of it was. I befriended people of many different faiths and when I went to poke holes in their theology I realized much of my criticism could be directed at my own as well.

Still took me several years to switch from calling myself "Catholic" to "agnostic" and then finally to "atheist." But eventually I just found that the only reason I held onto the label or went through the motions was due to social pressure and guilt. Once I accepted that, making the jump to calling myself an atheist was just obvious. I'm still willing to listen to evidence that theism is true or gods exist, but I have heard absolutely nothing that has been convincing.