Instead of going into a rant on the many points on which I disagreed with Maher (there are certainly many - not all Muslims are violent extremists, for one, Christians and Jews are not required to believe that a man named Jonah literally lived inside of a whale/big fish for three days, and fairy tales speak to the human condition just as validly as do religious parables), I will point out his one major and manifestly brilliant truth, and his one major and manifestly impressive fault. A man's greatest virtue is also his greatest vice, as they say.
Five minutes from the end of the film, Maher quotes (and this is from memory, so I apologize that it is paraphrased):
There is only one reasonable standpoint. It is not the arrogant certainty of religion, but doubt. Doubt is inherently humble.This is an amazing gem of genius. He's right, and he's more right that he is probably even aware. All religions, whether we acknowledge it or recognize it or not, teach that God - the ultimate Truth - is also ultimately unknowable (and so he does misspeak when he calls it the "arrogant certainty of religion;" what he means is the "arrogant certainty" of anyone who believes they're right and everyone else is wrong). No one has faith so strong that they do not have doubt, for doubt is a part of our innate human nature. It is part of what makes us human. We are, and must always be, searching, learning, seeking, asking. We never know all there is to know, nor can we, for we are human. Doubt is not a sin, as perhaps many misinformed people would have us believe. Doubt is indeed inherently humble, because it is the explicit and implicit acknowledgement that we don't know all the answers, and this makes it virtuous.
Continuing, however, Maher then authoritatively tells his audience to grow up and "give up" religion before we destroy each other and ourselves. His doubt - that virtue which, for one brief, shining and glorious moment, he understood to mean that he didn't understand - had transformed into an ugly arrogance, the very kind he was defaming. When doubt is preached as the alternative to faith, it has become, not a virtue, but a false idol. His doubt, in his mind, had become worthy of praise. He spent the remaining five minutes of the movie showing file footage of war and people in "religious" hysteria, claiming that all evils had been wrought on the world by religion, and by supposition claiming that his anti-religious doubt was therefore the cure for the world's ills. From that one brief but beautiful truth, he descends into the pride against which he rallied, and that is his one major flaw.
In the end, the movie will make you angry, unless you agree with Maher completely. That's fine. It has served its purpose if it makes you question and think and want to do something about it. But if you approach the film with the wrong mindset, you are destined to only become angry, and have nothing good or productive come from it. It is only his pride which offends our own. Learn from it if you will; "whoever has ears to hear, let him listen."