Religious passions are again driving world politics. The quest to bring political life under God’s authority has been revived, confounding expectations of a secular future. In this major book, Mark Lilla reveals the sources of this age-old quest—and its surprising role in shaping Western thought.The story could not be more timely. Most civilizations in history have been organized on the basis of a political theology – a myth or revelation about the correct ordering of society. Yet due to a crisis in Western Christendom nearly five hundred years ago, a novel intellectual challenge to political theology arose in Europe. By portraying religion as an expression of human nature, not a divine gift, modern Western thinkers found a way to free politics from God’s authority and build barriers against destructive religious passions.But the temptations of political theology are always present, even in the West. As Lilla vividly shows, the urge to reconnect politics to religion remained strong and took novel forms in modern European thought. By the Second World War a forceful political messianism had arisen, justifying the most deadly ideologies of the age.Making us question what we thought we knew about religion, politics, and the fate of civilizations, Lilla reminds us of the modern West’s unique trajectory and what is required to remain on it.