The longer you are here....you will see that this question is asked weekly by someone.
Here's a recent example:
[agnostic.com]

I gave up trying when they wanted me to memorize the books of the bible to join youth group...way too much work for very little return.

In my youth, I was seriously considering a religious life, but after reading the bible, and being told there were no answers for many of the great questions of life, I abandoned the idea and my faith. Atheism was a great relief for me.

My mother was a Jew who didn't know the first thing about Judaism, and my father was an ex-Catholic by the time i was born. So even though both of my parents believed in God, i was not indoctrinated into a belief system. By the time I knew the Easter Bunny, Tooth Fairy, the Sandman and Santa Claus weren't real, I had thrown this God character into that same category, at least in the back of my head, i didn't really give it much thought. Then when I was eight years old a Catholic family with a son my age moved down the block from us. This kid really believed that if he didn't make it down to the church every Sunday, he would burn in a lake of fire. Forever. Even at the age of eight I could reason enough that I said to him, "That just doesn't make any sense." So that was really the aha moment for me, when I realized I wanted nothing to do with absurd fairy tales. Were I to have chosen a , well the pagan ones, I'd read quite a bit about the Greek and Norse gods, and they made a lot more sense, because they weren't any more emotionally evolved than us humans, they were just as petty, vindictive, and bloodthirsty as we are. I knew enough about bible stories to know that the God (of the old testament, at least) was a totalitarian monster; anyone would give that bastard a way to find them, let alone worshipping him and proclaiming that, "God is love." was beyond me, I wanted nothing to do with it.

It was 2-3 years ago for me, but I had serious doubts for several years before that. I finally figured out I was an atheist at the age of 46.

I was never brought up to believe in God, but I think I was in my teens when I realised that God was incredibly unlikely... it was a combination of physics, chemistry and literature that made me think science made a lot more sense than religion.

But even so there was a long shadow of religious concepts, there was a long period where I called myself more an agnostic rather than an atheist, and ideas of hell and the devil troubled me for a long while as well. It takes time to shed those ideas, to deconstruct them and move forward.

It's been three years for me. I realized the only reason I held the belief was because I was taught by my parents to believe it...

As soon as the word bullshit entered my vocabulary I knew straight away where to apply it

Around the time I was 12, least conceptually. that point my mom left it up to us kids to continue going to church or not. It was no longer forced on us. Took a few years of going back and forth on the idea until the past 2 years I finally realized God and were just ways for people to accept things they don't understand (despite the slew of contradictions).