I consider myself agnostic, and saying I believe in god isn't quite right because while I believe in some kind of force out there, I don't believe in the very defined and personal deities of most religions.
The turning point for me wasn't about whether or not I believed in God or even whether or not I believed the words of Jesus, it was about religion itself.
I grew up in a family that was religious seemingly only out of fear. My mom pretty much never went to church but clearly always felt guilt for not going, and growing up she and her siblings went through a time period when their parents became born again and suddenly everyone in the household had to abide by very, very strict rules. It was all-but book burning. They relaxed but the guilt and fear stuck with every single one of them, and they all express it in their own ways. As I was growing up my grandmother would constantly ask my mom if I had been saved, my grandparents always talked about how various things were evil and I grew up thinking that every other religion was the equivalent of devil-worshippers. Buddhism was a big target for my family, oddly enough. I heard a lot how the buddha was a false god and so on.
So as I'm coming into adulthood I can't help my insatiable curiosity about all other religions, and started researching what it was that each believed. They all, in their own way, expressed the "golden rule" as a main tenant. I found that several talked about types of rebirth and reincarnation as well. That was when I began formulating the idea that each religion may have its own methods, but the message is essentially the same. It was years before I made a real break with the Christianity of my upbringing, to the point of realizing that though I agreed with much of what Jesus said, Christianity itself just felt wrong to me (as does every religion). Through the course of going to various churches I'd been exposed to people talking in tongues, to the cadence and trance inducing music of revivalist ministers, and people telling BS stories to scare kids into praying. As was mentioned by someone else, praying was always weird to me.
It was a long drawn out process and there was no single event that made me change my mind. It was little things over the years that added up less and less and less that brought me to now, being agnostic and though I still follow the words of Jesus and Buddha and others like them, I reject any of the religions that have sprung up around these people. To me, religion is flawed because of groupthink. It influenced religions in the past, it influences people today, and for some reason I have always been outside the group mentality. I never meshed with the rest

shocking I know!
The most important thing to me is seeking the truth. I will go so far as to deliberately pick apart my own thoughts and beliefs, breaking them down to try and figure out the psychology behind my ideas and establish what parts of my beliefs are genuine beliefs and what parts come from a need for something. So I guess a better way of saying it is I am always of two minds, two different egos constantly pecking at each other and trying to find the balance in between where real truth lies. The 3rd side of the story, the impartial side which has nothing to gain by spinning the story.
Also in regards to some comments in the OP: I have actually met some atheists who are atheists because their parents stuffed religion down their throats as kids and they rebelled against it. They tend to lash out at the religious unprovoked and have a chip on their shoulder against god and religion as a whole... but they are a small minority. I just wanted to say that it does happen, and people who've known atheists such as this may think most atheists are this way... kind of like thinking most african americans love grape soda. Maybe they do, maybe they don't, but making an assumption based on a label is unfair.