I was sent to Bible study as a kid and spent my share of time in church growing up. I took a Bible as Literature class in high school because I wanted a better understanding of what the Bible actually said. When my family was young, my wife and I took our first two children to two different non-denominational churches on and off. It was never a very good fit for me personally because I always felt in the back of my mind that it was all a fairy tail.
I spent most of my 20s and 30s trying to reconcile the world around me with the Biblical teachings of Christianity, but I always came back to the same questions: If God is omnipotent, loving and has a plan for us all, how does that mesh with the evil we see in the world? How does a loving father allow innocent children to be abused and killed if he has the power to stop it? How many prayers does it take to cure a good Christian of cancer? What kind of plan does he have for a carload of family members killed by a drunk driver?
The only logical answer I could come up with is that He is letting us flounder and try to make a go of things on our own so we learn a lesson. Kind of the same way a loving parent might let a rebellious child try and fail so they will figure out they can't do things on their own. After all, we did disobey God and eat from the treat of knowledge rather than be happy idiots in the garden of Eden. Maybe all the suffering in this world is worth eternal joy in Heaven after we die? Right? Maybe?
But the Bible is full of too many contradictions, illogical impossibilities, archaic rules and plain old evil ideas. It takes a huge suspension of disbelief, logic and scientific ideals to embrace religion, and it's as if religion was designed to keep us from thinking and to accept our position in the world. The idea that your reward will come after you die sounds like the biggest scam ever perpetrated on mankind, frankly.
And when then see religion used to justify hatred and to hurt the innocent among us it just cements for me that there are only two possibilities: Either God is an asshole who likes seeing us suffer for defying him, or he probably doesn't exist and we are the assholes, and some of us like treating our fellow man like shit. I'm going with the later until God shows himself. And if he does he will have some explaining to do.
EDIT: Or a third possibility could be that we simply don't fully understand the nature of our existence and who or what may be out there and are making things up to satisfy our own need to know. This would explain why there are so many different flavors of religion. While the existence of the Christian god doesn't seem very plausible, IMHO, that doesn't mean I can say for sure what is out there or that there is no god at all. This is why I will consider myself skeptically agnostic until I see some scientific evidence of what's "out there."