In this trenchant examination of Christianity's dark side, a criminologist argues persuasively that high rates of violent crime in the United States can be correlated with Christian conservative attitudes, especially in regard to social mores and politics. Of particular concern is "Christian nationalism." Supporters of this movement argue that America was founded as a Christian nation and they work to install their fundamentalist brand of Christianity as the dominant factor in American political and social life. Far from being a fanatic outlier sect, this group is shown to have significant cultural influence, especially in the American South. Not coincidentally, the author suggests, the South also has the highest homicide rates.

Noting the violent biblical passages often cited by religious conservatives, their sense of righteousness, their dogmatic mindset that tolerates no dissent, and their support for harshly punitive measures toward "sinners," Peterson Sparks shows that their worldview is the ideal seedbed for violence. Not only does this mindset make violent reactions in interpersonal conflicts more likely, the author says, but it exacerbates the problems of the criminal justice system by advocating policies that create high incarceration rates. The author also devotes particular attention to the victimization of women, children, and LGBT people, which follows from this rigid belief system.

While not resorting to a blanket condemnation of Christianity or religion as a whole, Peterson Sparks issues a wake-up call regarding conservative Christianity's toxic mixture of fundamentalism, authoritarian politics, patriotism, and retributory justice.