Increasingly, the future is becoming a theme for theological reflection. In the background we can detect a growing concern among many people for the future of faith. Does faith have any future at all, and, if so, where in all the confusion of today's trends will we discover its embryo? But the problem of the future assails not only the believer. In the ever more rapidly advancing process of historical evolution, man is confronted with enormous opportunities, but also with colossal perils. For him, the future is not only hope, but sorrow-a nightmare, indeed. He cannot avoid asking what part faith can play in building tomorrow's world. Joseph Ratzinger, now Pope Benedict XVI, approaches this problem of universal concern from a variety of angles, bringing his deep personal faith and theological brilliance to bear on these serious questions.