Okay, now before you say "of course it is,", let me explain a little. I'm not talking about the current problems of separation of church and state, abortion, stem cell research, and gay marriage that are brought upon by religious activists. I'm talking about the fact that even passive religious views affect the country in the sense that they make believing whatever the fuck you want okay, regardless of what evidence there is to support it.
Now generally I believe that if intelligent people are provided with the same information and try to minimize their personal bias, they can come to more or less an agreement after discussing an issue. But if you look at our country, we are more polarized politically than we probably have been since the Civil War. Why can't we discuss things rationally? Why can't Republicans and Democrats come together, have a good debate, and decide what's best for the country? Well, I would argue that religion is the primary obstacle in having a society where compromise and intellectual discourse takes place.
Religion gives people an excuse for not having reasons for what they believe. The Republican or Democratic pundit can sit on their "debate" show and just ramble off the party position while demonizing his opponent. Rambling on about your dogma while you try to make out the person who disagrees with you as being evil...hmmm.....where have I seen this tactic before? Instead of using reason to find out the best solution for our country's problems, they can simply passionately defend the beliefs that they were raised with. Truth and evidence take a backseat. How can we expect them to use reason to form their beliefs when religion makes it perfectly okay, even honorable, to believe things purely on faith? What kind of an example is that?
In a society where religion has a big effect it is difficult to have an intelligent debate with someone and come to a reasonable solution. For example, I often have discussions on various topics with my friends. We'll be moving along nicely for about 10-20 minutes. We'll see what each other believes and then we discuss things and try to come to a consensus. Sometimes though, my friend responds with "well, I see your point, but I see it more along this christian argument...". Well shit, I guess I get off the train here. The debate is over. I can't see his position because I refuse to take Jesus as my "savior" by faith, and he doesn't want to give up his afterlife.
As nuclear weapons become easier to get, it is critical that we can discuss things rationally with the rest of mankind so that we can come to reasonable solutions that save us from going to war. But if so many people believe things with no justification, how could we ever come to agreement?