I used to believe in God and honestly even recently went to a church with a co-worker. They claimed to be open-minded and that they don't force their beliefs on others. I had a great time for a few weeks, but after being told how men and women should live and how homosexuality was an affront to God, I never went back.
Something about religion makes people feel so strongly about their views or interpretation of the bible that they will impose their views on others or intimidate others to agree with the way they think. Once I never thought I would be an atheist and I even struggled to call myself one as I've also seen some atheists use their beliefs in a similar method to force those who believe to not be able to express their beliefs. That is also wrong to me as people should just leave others to their own opinions.
When people start to talk about how I feel about religion, I tell them that I never read the bible. Their first reaction is to tell me that I should and even try to get me to go to their church or recommend editions of the bible to read. My response to them is that I will do that only if they go without religion or church for a period of a month. They never want to do that, so I tell them that I won't read the bible. Enlightenment goes both ways and if you want me to see your way of seeing things, you should experience mine as well.
God and religion should be about bringing people together for the betterment of others, but it never really seems to do so. There are people who've voted against gay marriage in California (Prop. 8) due to religious convictions. I assume that they want to force homosexuals into a "separate-but-equal" civil union. Marriage should be a legal institution and not a religious one.
In Pennsylvania, they won't consider your marriage legal unless you have the ceremony done in front of a church congregation. This is fine except there are no atheist churches in my area or really any others. You may be able to go to the city hall to have the ceremony also, but again, religion has limited the freedom of others.
I have never known of atheists or agnostics fighting with each other over who doesn't believe in God more. While I don't want to force others to not believe in God, I shouldn't have to be forced to believe either. Respect my beliefs and I will respect yours. We don't have to like or agree with each other.... only live with each other. If I'm wrong and God is real, then that's for me to deal with. Perhaps I'll be sent to hell which will be my only salvation from those who overly preach the workings of God. Maybe it will be the opposite as I never used the word of God to negatively affect or hurt others that I will end up in Heaven..... Either way, life's too short to worry about what happens later. Until that day, I choose not to believe, but that's only because of how those who do believe portray themselves.