This work is the first master book of the great traditionalist metaphysician, Frithjof Schuon. Here is a book which allows to give a convincing account of both the unity and the diversity of the great religions of humanity, without falling into syncretism or a leveling and relativistic unanimism.
Christentum – Islam: Ausblicke auf eine esoterisch Ökumene (e-Book)
In this work, Frithjof Schuon compares Christianity and Islam and also looks at confessions within these world religions: Protestantism, Orthodoxy, and Shiism.