While watching Religulous, I noticed some things that kind of jumped out at me about the movie. One thing Bill Maher does is pretty much find the most extremist of religous people to question rather than just the normal people that go to church or whatever. This isn't necessarily a bad thing, but it makes it easier for him to pick on or make fun of the person hes questioning.
Another thing Bill Maher does is incorporate comedy with religion, a thing that isn't heard of very often. I think he does a good job doing so, seeing that religion is usually a serious subject people don't like to kid around about. He's obviously a pretty smart guy and he knows his stuff about most religions, which makes this movie enjoyable to the end.
A clip from the movie Religulous