I was raised in a family who didn't force any kind of religious views on us. Their view was: 'decide for yourself.' But England is a protestant country, so my primary school was actually a Church of England school and it was a fantastic primary school, I wouldn't say anything bad about it. Christianity certainly was promoted by it, we even had moments of reading the bible, we prayed during assemblies. They were tolerant too, two of the girls in most of my classes through out school were Muslim and they didn't have to get involved with Christian practices. When it came to Christian holidays, it could get religious - I remember the assemblies in the assembly hall where they went through a lot of trouble to make Christmas special...even if Christianised (lighting of candles, hymns and prayers). But I actually have fond memories there. Going to that school did have me believe in God and I thought Jesus was real. The school was very effective at teaching children, things were learned there people still had no clue about in secondary school (get this, I was even in the choir...at least for a brief period; I realised that I can't sing for shit). And when it came to teaching religion, they taught about all the world religions, more so than my secondary school did. I even learned a little bit about Sikhism (the Gurus) and Buddhism and even bits of the Norse mythology now that I come to think of it. From those classes I do very distinctly remember the Buddhist story of Siddartha Gautama giving up his life of being a prince to understand human suffering, I still love that story.
Interestingly, my becoming an atheist happened whilst I was still at the school. It was actually about the time I discovered metal actually. My brother got a Metallica album and Marilyn Manson too. I think there were a few things MM said that got me thinking along the lines of questioning God & the bible through the problem of evil. Whilst I am sure my answers weren't well researched and deeply considered but then I was 9 or 10. I didn't even know what an atheist was, I never even heard of the term. I went by the name of an 'anti-Christ' because not only did I not believe God was real any more, but I thought Christianity was evil. In class, when the bible came out I almost defaced the bible and also placed my hand on the bible and said things like "fuck God" away from ear shot of the teacher, just enough for my best friend to hear and laugh (it was 'naughty', he wasn't exactly a well behaved kid, don't think he saw it as me hating the bible). And that makes me sound like I was a depressing kid, but actually I was an extremely happy kid, on top of the world most of the time.
My form tutor at secondary school was a strong Christian and he used to teach religious studies, so he and I often got into conversations about 'religion', he was quite open about it and he was a very open minded and tolerant man and I respect him for it. I even brought in the Satanic bible to class, he found it funny and read the first chapter, so he was a good sport. It was during one of those conversations that he told me what an 'atheist' was and also was a 'theist' was. He didn't give the BS talk we see many people give when trying to describe an atheist now, but actually gave me the definition I still stick by today: a person who doesn't believe in any gods. It took until I was 14 to realise that actually many people I liked and respected were Christian and that maybe Christians and Christianity weren't as evil as I claimed them to be. I also find myself being more and more open minded. I ended up studying religious studies and philosophy and have a number of philosophy books on my shelf and have considered a great deal of arguments and even came here to refined my thoughts and strengthen my own arguments, but to also listen to the arguments of others and to learn more, unfortunately, it is rare for somebody to offer something worthwhile or something we've not heard a thousand times before.
At times it does get frustrating, but the best thing I like about this place is: when you're wrong, people will make the extra effort to show you where and explain how, okay, you might not always agree but it really brings you to analyse your own argument in depth...as long as you're not that 'la la la I'm not listening' type, when I've disagreed with fellow atheists, I've had my weak arguments put on display and picked apart and where my information has been inaccurate it has been corrected. I try to return the favour by doing it to others, however, it doesn't always work out as people think you're being intolerant or are trying to demonise them or are just trying to piss them off, but thankfully there are the handful of those who get it and engage with it...I like those people, even when we standing at opposite ends they're people I'd probably buy a beer.
That's an in depth answer to your question. I figure it needed a full answer, with a before and after to put my atheism into a better context.