Cringe-inducing
I really appreciate the work of Dawkins and Krauss, but I found the document very difficult to watch. One constant argument by the believers is that atheism is just another religion. That of course is not true. The Unbelievers however painted an image of Dawkins and Krauss as some atheist Jesuses with a massive following. The constant cuts to clapping audiences and people praising the stars of the film for changing their lives, made even me feel uncomfortable.
The film didn't seem like a biography of Dawkins and Krauss; what led them to their current paths etc. It didn't really give the religions any say - even to be debunked by Dawkins and Krauss. It really felt like a complete circleje... back-patting fest. I felt like I was watching a documentary about Justin Bieber, made by a 13-year old girl.
It's not like atheists need any more assurance regarding the correctness of their views of the world. However, if the purpose of the film is to make people question their faith, it fails hard at it.