I have not read Mark Lilla's book The Stillborn God, but a few months ago I critiqued his New York Times article, which was adapted from the book.
I have found a critique of his book that offered this quote:
A first core problem of the book is the very beginning of the story: it buys into the simplistic myth of religious violence and secular peace, resting on the unsubstantiated empirical claim that “religion” (whatever that is) breeds violence whereas institutions of liberal democracy foster peace (current world conflicts in the name of “democracy” not withstanding). Thus Lilla repeats the liberal alarm about religion’s “passion” and “fervor” as the incubator of violence—passions to be curbed by the machinations of Leviathan and, later, the liberal democratic state. But this is a distinction that is untenable for anyone who has ever attended a professional sports event in the United States. It sounds as if Lilla has never witnessed the fervor and passion incited at the opening of a NASCAR race when the dancing colors of the flag are mingled with the iconography of a military fly-over. The opening prayer certainly doesn’t excite the same passions!It never ceases to amaze me when non-religious people assert that religion is an inherent fomenter of violence. Apparently these people have never heard of religious pacifists like the Berrigan brothers, Martin Luther King, or large number of the world's Quakers, Bretheren, and Mennonites. By the same token, it is equally absurd for religious people to accuse atheism of having an inherent relationship with violence or injustice, as the Pope did in a recent encyclical.