From German South West Africa (Namibia) to the First World War to Rwanda, humans in the twentieth century demonstrated a terrifying capacity to inflict violence upon specific groups of people. The global occurrence of these events indicates that they are limited to no single region, religion, political system, or ideology. Further, perpetrators, “bystanders” (or implicated subjects), victims, and collaborators represented many different religions. We will examine the role played by religion and religious people in the Armenian genocide, the Shoah, the Cambodian genocide, and the Rwandan genocide.