In many low-income neighborhoods in El Salvador, two groups have significant influence over the public sphere: gangs and evangelical churches. Members of both groups often belong to the same families, use similar organizational strategies, and engage each other in local marketplaces. Pastors and gang leaders compete for power within communities while informally sharing community governance. Entanglements even occur within formal organizations: Gang members can be found in churches and faith-based organizations, while an evangelical presence exists within prisons and other gang-controlled spaces.

Blood Entanglements shows the importance of religion in gang-controlled neighborhoods in El Salvador through extensive empirical data and the personal stories of people who live there. Stephen Offutt uses the notion of "entanglement" to explain how and why evangelicals have such frequent and often intimate interactions with gangs, which are groups that many evangelicals believe are evil. Entanglement, he shows, also sheds light on how evangelicals engage with Latin American society and social problems more generally. The book concludes with policy recommendations for reducing gang prevalence and violence in areas with a prominent evangelical presence.