What are non-Christian religions? How is God related to them? How do they relate to Christianity? In this original book, Iain McGee explores five Christian theologians' answers to these questions. The study spans the history of the church, covering figures from four different continents: Justin Martyr, Augustine, John Calvin, Jonathan Edwards, and Daniel Strange. Focusing on the revelation-religion interface in the writings of these scholars, McGee outlines and analyzes their varied understandings of Logos illumination, the prisca theologia, and the demonic, alongside the relationships between them and their impact on non-Christian religion. McGee forwards an argument that each theology can be considered a biblically informed, contextually reflective, and reactive response to significant religious challenges faced by these Christian thinkers in their attempts to demonstrate the uniqueness of the Christian faith.