" What is religion and how does it dialogue with other areas of spiritual life such as science, philosophy, ethics, art or politics? Why is it Is it impossible to demonstrate the existence of God as one demonstrates a physical or mathematical truth? Addressing believers as well as atheists and agnostics, Luc Ferry, follower of a secular spirituality, highlights the multiple meanings of the main themes of the Christianity Rather than writing a history of theology, Luc Ferry attaches "Philosophy and Christianity for Dummies" published by First Editions, to explain the strictly philosophical part of Christianity, with regard to Judaism and Hellenism as well as certain great secular spiritualities.