- A Hobbit, a Wardrobe, and a Great War: How J.R.R. Tolkien and C.S. Lewis Rediscovered Faith, Friendship, and Heroism in the Cataclysm of 1914-18
- The Searchers: A Quest for Faith in the Valley of Doubt
- The War for Middle-Earth: J.R.R. Tolkien and C.S. Lewis Confront the Gathering Storm, 1933-1945
- God, Locke, and Liberty: The Struggle for Religious Freedom in the West
- The End of Illusions: Religious Leaders Confront Hitler's Gathering Storm