Hector Avalos is one of my heros. He is a professor at the University of Iowa and an atheist. Concerning biblical matters, he is the absolute go-to authority.
In a recent column marking the 9/11 anniversary he thoroughly deals with the controversy regarding involvement of religion in violence.
I would like to add a point of my own. The way religious violence is covered in the media betrays a deep deference, which religion did not earn and does not deserve. You have heard of "religious charities, hospitals, benevolence". But "religious division/strife/bloodshed etc."? No way. The adjective used is always "sectarian". Nothing negative can ever be conceivably associated with religion.