It seems like some of the people who define themselves as "strong atheist" were never "real believers" in religious gods, while others started out as strong believers. In some cases, they were strong believers in especially rigid sects. I'm curious about what led people to not only lose faith but also become what they define as "strong atheist". In my own case, the loss of faith was due to reading the Bible. Being raised in a fundamentalist Baptist background, I was taught that either it's ALL true, or it's not - that we couldn't pick and choose. I started out as a strong believer in the Bible and the Baptist church. Then literal readings of the Bible led me to realize that the internal contradictions could not ALL be true. So I lost faith, completely.
The "strong" atheist part was due to excesses and psychological and physical brutality that I see in religion, and the lies and hypocracy that I saw in both my original church and in the powerful leaders on a more general national, and international, basis. Even stronger with recent events, in the US and in the Middle East.
What leads others, or most people, to "strong" atheism, as opposed to just not beleiving?