The belief in a single, all-powerful God who created the universe and demands exclusive worship — the founding theological claim of Judaism, Christianity, and Islam that shaped the religious, philosophical, and political history of half the world, and whose logic of exclusive truth generated both civilization and persecution.
Monotheism is one of the most consequential ideas in human history — and one of the most contested. It gave the world universal ethics, the concept of human dignity, and the idea that history has a direction. It also gave the world religious persecution, holy war, and the conviction that those who worship differently are damned. The same theological move that generates universal human brotherhood generates the logic of the crusade.