For the historical background:
Personally, it was when I was 7, the school taught me about dinosaurs and so on, what taught us the scientific observations, meanwhile, the catechism in which my mother sent me during 2 years, told me about Genesis, the creation in 7 days and so on... Damn, there were something wrong in one of both, I chose dinosaurs and school, and, even if I keep some distance with what science can say, the History shew us that some interpretations of reality can change, I had always been reinforced in this choice until now...
Then, I don't believe in what some call "God", because of the analysis I have of my knowledges, of what I observe, and of what I feel. All of this leads me not to believe in this and leads me to other kinds of conclusion than this one.