I feel the need to clarify on something...
There are in fact religions that do not have gods, Buddhism is one of them, as well as Confucianism. I think a better name for this thread would be more on the existence of god, because I see less talk about religion then I do on god...anyways, enough about my perfectionism... >.>
Religion has evolved over time, many ideas included in the most common religions today were stolen from religions previous to them, which is a dead ringer to me that they are false. Alot of religions I know of preach peace and love yet they simultaneously preach war and suffering, and the war and suffering comes out a hell of a lot stronger.
If you look at the old testament of the bible, you will notice an incredible ignorance among the people, especially in Exodus when God makes food rain from the sky, and they decide to worship a pig idol that hasn't done a single thing for them. Who could possibly be that ignorant? Maybe a few people, but I doubt a whole group of people would all be like that, it's inhumanly stupid.
I do however praise religion for keeping some "lesser" minds(not to say all religious people are lesser) in check and from doing unsavory deeds, and also providing people with hope, and keeping them from doing things such as committing suicide(Even me in my atheism value human life).
The biggest problem with religion though(and why you'll see atheists try to sway you from your beliefs) is that it seems to compete with science, and although I'd say competition brings out the best in us, people will simply ignore and deny fact or reason if they consider it a threat to their religion. Richard Dawkin's recently came out with a new book about Evolution called 'The Greatest Show on Earth' and the Uncommon Decent(which is an Intelligent design group) posted on their website that they are going to reject everything in Dawkin's book before it was even released.
Religion isn't a problem necessarily, but don't let it blind you, don't let it make you think you're superior, and don't let it control your life, or it'll come back to bite you in the rear-end.
Uncommon Descent Website