I’m looking forward to hearing from those interviewed in the movie about whether they felt Maher depicted their views fairly. Given that one of Maher’s criticisms of religion is that people proof-text – i.e. find in Scripture a quote to prove whatever they want – it’s incumbent on him to be honorable in his use of interviews.
As it happens, I know about one statement he cites. In the beginning of the movie, he offers this quote from our second president, John Adams: “This would be the best of all possible worlds, if there were no religion in it.”
Wow. That certainly provides stunning support for Maher’s thesis. Did Adams really mean that? Well, no. Here’s the full quote from Adams, which came in a letter to Thomas Jefferson, April 19, 1817:

“Twenty times in the course of my late reading, have I been upon the point of breaking out, ‘this would be the best of all possible worlds, if there were no religion in it.’!!! But in this exclamation I should have been as fanatical as Bryant or Cleverly [two clergy from his childhood]. Without religion this world would be something not fit to be mentioned in polite society, I mean hell.”

Slightly different meaning when you see the rest of the quote, eh? Sort of makes one wonder how scrupulous Maher was with the rest of the editing. Perhaps this is an anomaly.