https://brasiliensis.cerm.org.br/index.php/brasiliensis/article/view/127/version/127 How can we explain to today’s world, in a a few words, what the Christian faith consists of? Joseph Ratzinger sought to summarize the basic form of the Christian faith by addressing some of the statements in the chapter Excursus: Structures of the Christian Faith, from the book Introduction to Christianity. From the analysis of how Grace influenced Ratzinger’s life, this article revisits the reflection he developed from the perspective of the theology of Grace. The six principles presented are a kind of formula of the essence of Christianity, based on a single principle which is love, accessible to man by the redemptive action of Grace