There are many reasons why I left the faith, but one of the key reasons was that I had read the bible. There is an ongoing joke among atheists that states 'How do you convert a theist into an atheist? And the answer is that you should let him read the bible.' Regardless of context in the numerous cases of cruelty perpetrated by the biblical God against humanity, I found it hard for me to believe in him and found it more reasonable to accept that natural disasters for instance or birth defects are natural occurrences rather than acts of God.
One of the many things I found irritating about being a Christian is that you have to constantly defend the actions of your god at the expense of degrading yourself. We are supposed to be thankful to God everyday for giving us life and sacrificing his son/his self for mankind so that we can have eternal life in some imagined paradise up in the sky. The very idea of some creative being living in the sky or some other dimension, watching us, and dictating how things play out in every single individuals life is outright ludicrous. I've always said that when someone is praying he is supposed to be talking with God but when someone is talking to himself or some imagined person or friend he is considered mentally ill. I personally don't see any difference between the two acts.
The idea of people in a church singing to the imagined guy in the sky with arms raised above their heads jumping and carrying on is sad and at the same time looks foolish. I tend to pity Christians in general and Islamist who have to bow their heads in submission and pray 5 times a day facing the East etc. I personally think that anyone how does these things is mentally insane and completely deluded and out of touch with reality.
Life in general is what it is and I don't see us as greater than the animals, I see us as equal with them. We are all mortals and we have an expiration date that comes with our life, the thing is we don't know when that is. Some die at birth or in the womb, while others live to be a ripe old age and get to experience a lot of the things that life has to offer. Why waste your life praying to a deity that there is no evidence even exists? Why waste your time putting everything into the service of this deity and even sacrificing your life and what you want to do in exchange for your perceived idea of what this deity wants and desires?
In fact, what does this deity want and desire? Well, if you read your bible it seems that he can't get enough of worship and praise. He thrives on your submission to him and your complete obedience to him. He likes constantly reminding you that if it were not for his mercy you would not even be alive or spared his torment at the place he himself has made called hell after you die. I personally don't take too kindly to threats so the old torment after death thing does not sit well with me, and submission to an imagined authority fits in that same category.
One of the things I find most fascinating about life is its randomness and unpredictability, we are here today and may be gone a minute from now. That is why I live my life to the fullest each and everyday, without God life just makes so much more sense to me than if there were a god at all. I don't need to pray, I have no need for worship, I am content to enjoy the mystery and wonder that is life till it's my turn to check out.