Got this from here.
Highlight the important parts of your religious development, grouping it by age.
My parents decide that it wasn’t necessary to baptise me.
We moved from the big city to a small, very catholic village where we stood out like a sore thumb. A lot of hostility because of a lot of things, but mostly because we weren’t good catholics. Or no catholics at all, in my case. Things didn’t bode well for me and catolicism.
Things pretty much stayed the same: While I was fascinated with the stories from the bible, they were stories to me, not factual accounts and stood on their own – entirely separated from the church in my head. Church became a no-go more and more.
I wanted to find the church for me. I still believed that there was something out there, some higher power, even if I refused to think about it as “god” or picture a man with a white beard. Dabbled in Buddhism a bit, but never really seriously.
Short spiritual phase, mostly lived by reading Paulo Coelho. I lived in Brasil at the time with a very religious (baptist) host sister. My aversion against churches grew after I was laughed at by her and her friends for saying that I “believed” in evolution.
After spending a long time evading the question of what I believed (if someone asked, I’d usually say “science”) by settling that there’s no church for me and that I didn’t see any higher power in the day-to-day life anyway and that the only place left for god in my world was before the Big Bang, I had an epiphany: I just didn’t believe in god. It really was this one moment, I remember it perfectly, where I just thought: “Actually, I really don’t think that there’s anything out there.” And suddenly, it was like a weight fell off my shoulders and I knew that this was something I really and wholeheartedly believed to be true.
Then I just had to spend another 9 months in Africa, where the missionairies screwed people up so bad that they couldn’t accept that on the one hand, they couldn’t convert me and that on the other hand, I didn’t want to convert them, either.
After that, my atheism was bullet proof.