Joseph Ratzinger s Introduction to Christianity has three prefaces (from the years 1967, 1969 and 2000). It is interesting to note that the German theologian dedicated himself, particularly to the last one, to describe the sociocultural context – ideological or philosophical-political, it may be said – that emerged in the thirty years that followed the first appearance of the work. That is, it presupposes a diagnosis of the time in which faith must be announced, transmitted and, also, a critical look at which theology took in this period. In this sense, the book is also an introduction to the contemporary world or even an analysis of the relationship between Christian faith and the world. The fi rst chapter of the Introduction is precisely entitled Believe in the world of today. Thus, this research aims to present the conception of the world of today exposed in the work, with particular attention to the currents of thought that characterize it. And to complete the exposition, the article will link Ratzinger s description in the Introduction with pronouncements made during his pontifi cate, such as the answers given by him at his meeting with the Clergy of Belluno-Feltre and Treviso on July 24 2007, in which he refers to the same events and dates that he analyzed in the preface of the year 2000. Thus, the reader will be able to see the worldview with which the Church must dialogue (or confront) from the perspective of J. Ratzinger-Benedict XVI.