What is faith? How do you conciliate with the prospects of modern man? What place does it have in a world where everything that is tradition is now overcome, and man feels at home only "in the owe of progress and the future"? For a theologian Pope as Joseph Ratzinger, the Christian faith "is something more than an option for a spiritual foundation of the world": "His central formula does not say 'I believe something', but I believe in you '. It He is the meeting with Man-Jesus ". The meaning of the world is all in this personal meeting: the "you" of Jesus true man and true God "agrees the promise of an indestructible love, which not only aspires to eternity, but it gives it". The reflections collected in this volume - taken from "introduction to Christianity", the comment dedicated by Joseph Ratzinger to the apostolic symbol - depart from the "brackish water of doubt" which risks suffocating the believer as the incredulous and touch the mystery of God , the fate of Christ, hope and love-charity, the "true and total loneliness, that scary state that the theologian calls 'hell'", the immortality and resurrection of the dead, the church and its "paradoxical Structure of sanctity and misery ". Today, after the unprecedented choice of the renunciation of the ministry, these thoughts represent the spiritual legacy of a great pontiff, the gift that a clear and profound mind offers to the meditation of men and women in search of answers to the fundamental issues of existence.