This argument has always been one of the more absurd arguments for religiousness in my mind. The idea that believing somebody makes someone happy is totally unrelated to whether that is actually true. It would make me happier if I believed that my bank was going to let it slide that I overdrew from my account today and not fine me, but that isn't going to happen.
Today I came across a quote by George Bernard Shaw, one of my favorite figures of the 1900's, summing up my views on this argument more beautifully than I ever could: "The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one."
I know from experience that drunkenness generally leads to greater happiness than sobriety. However, being a drunk is considered a waste of one's mind. If there is no God, then the argument that religion makes people happy is not a very valid one. If there is a God, it is not a necessary one.
What religious or political arguments do you find ridiculous not even because of the side it supports but because of the uselessness of the specific argument when examined?