My biggest problem with religion is that many people take anecdotal evidence as proof. People say they have afterlife experiences all the time, then again people say they have been abducted by aliens, or that they can read minds, or that that hedge fund is perfectly safe, but there is no concrete evidence that aliens have ever been here - in fact it might be impossible, studies have shown that people cannot read minds and that hedge fund has dissapeared and a fat cat got fatter.
I'm not saying that there is no god or anything like that, I'm agnostic in that regard, I wouldn't rule it out. Its just that there are no arguments that lead to evidence or proof of god. In fact I believe that's the whole point really, to have pure faith, to believe blindly.
I agree with Jessica on churches though, they are about money and control for the most part, there are probable some good churches out there but in general they are, or at least I think sometimes they are, a tool that people use to manipulate people by using their basic desire to be not dead.
The idea of not being dead after you are dead is a heck of a motivator and when you reward yourself with that comfort every time you think a faithful thought then you can become prey for those evil and imaginative enough.
Sorry, I do respect religious people, and I have a terrible fear in the back of my head that I'm gonna get dead and there'll be god shaking his head at me.