This book examines the world of religious conservatism in Christianity and Islam through a comparison of two eighteenth-century traditionalist icons, Jonathan Edwards and Muḥammad Ibn 'Abd al-Wahhāb. Spanning the globe from America to Arabia, this book explores the major themes in the lives and works of these most unlikely of bedfellows, the Reverend and the Shaykh. In many ways, Edwards and Ibn 'Abd al-Wahhāb are about as far apart as two figures could possibly be. Without minimizing their very real differences, however, this comparative study finds numerous parallels that beckon even the most conservative of Christians and Muslims to take a second look at their own faith, as well as the faith of the other. The numerous surprising congruences in the worlds of the Reverend and the Shaykh, as well as in their conceptions of God, humanity, and the faith of the other, suggest that we stand much to gain from a reassessment of long-held views that could lead to wholly new patterns of engagement. With implications in diverse fields such as politics, law, philosophy, theology, history, warfare and anthropology, this book unearths striking parallels in Edwards and Ibn 'Abd al-Wahhāb that have heretofore gone unnoticed or largely ignored.