I'll admit that my only interest in reading this would be to amuse myself or to understand the position taken by Sam Harris. It may sound obnoxious to say but I find the delivery style of Sam Harris or Richard Dawkins overwhelmingly stuffy, pretentious and interestingly dogmatic in their own way. Of course that's not any reason to ignore a book (save that I disagree with the overall contention regardless and that as far as I'm aware these New Atheists make some of the most blatantly obvious and repetitive assertions).
The one thing I will note here is a comment on the blurb at the top, to allow me personally to remember this idea if nothing else.
Galatians 1: 6-10
“Thousands of people have written to tell me that I am wrong not to believe in God. The most hostile of these communications have come from Christians. This is ironic, as Christians generally imagine that no faith imparts the virtues of love and forgiveness more effectively than their own. The truth is that many who claim to be transformed by Christ’s love are deeply, even murderously, intolerant of criticism. While we may want to ascribe this to human nature, it is clear that such hatred draws considerable support from the Bible. How do I know this? The most disturbed of my correspondents always cite chapter and verse.”
6 I am astonished that you are so quickly deserting the one who called you to live in the grace of Christ and are turning to a different gospel— 7 which is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ. 8 But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let them be under God’s curse! 9 As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let them be under God’s curse!
10 Am I now trying to win the approval of human beings, or of God? Or am I trying to please people? If I were still trying to please people, I would not be a servant of Christ.
The point being made is that when Christians judge so vehemently they are not applying to the true gospel but another gospel. They are applying to the gospel of the knowledge of good and evil - of law. The gospel where you have to work hard to end up as a good person and not an evil person. In reality the truth is that we all end up being on the wrong side of the ledger according to the gospel of grace and according to this gospel you don't have to work for salvation, you are accepted regardless of what you do not because of what you do. And I think that is something too many Christians haven't learnt yet...