"Ratzinger's move from Münster (in 1969) to the Protestant university town of Tübingen is one of the most enigmatic decisions in the biography of the later pope," writes Seewald in his biography. Although in his book My Life Ratzinger himself recounts some of the reasons. 

On the one hand, he was uncomfortable with the drift of his colleague from Münster, Johan Baptista Metz, towards a political theology, a very political theology. On the other hand, he was attracted by Hans Küng's invitation to join a theological renewal team in Tübingen. He was also attracted, much more so than his sister, to Bavaria, his homeland. 

Ratzinger was then an emerging figure, after having stood out at the Council as the trusted expert and inspirer of many interventions by Cardinal Frings of Cologne. Although he was initially interested in Küng, he soon found that their horizons did not coincide. Küng arrived at the university in a red Alfa Romeo, while Ratzinger rode a bicycle with a beret. 

They would meet again in 1981, when Ratzinger, as prefect of the Congregation for the Doctrine of the Faith, had to face the "Küng case". 

He would be in Tübingen for only three difficult years (1966-1969). "The School had a body professor of the highest level, although inclined to polemics." In addition, the intellectual atmosphere of the School changed completely: "The existentialist outline collapsed and was replaced by the Marxist one". 

It was a hope without God, represented also by Ernst Bloch, famous Marxist professor of the School of Philosophy and author of a famous essay on The Hope Principle. In that atmosphere, Ratzinger recalls: "I saw without veils the cruel face of this atheistic devotion". That was the famous '68 already in ferment, and it touched him closely: "At the time of the greatest confrontation, I was Dean of my School", member of several councils and "of the Commission in charge of elaborating a new Statute for the university".  

But there were not only complications. In 1967 it was Küng's turn to teach the Dogmatics course, and Ratzinger found that "he was free to carry out a project that he had been silently cherishing for ten years. I heard about experimenting with a course that was addressed to students of all Schools with the degree scroll Introduction to Christianity". 

"In 1967," he says in the foreword to the 2000 edition, "the impulses of the recent post-conciliar period were still in full effervescence: the Second Vatican Council wanted to do just that: to give Christianity once again a force capable of shaping history [...], it was once again confirmed that the faith of Christians embraces the whole of life". 

In a way, the amalgam of Marxism and Christianity and its projection in liberation theology wanted to achieve the same thing, but "faith ceded to politics the role of a salvific force". And in parallel, there was Western agnosticism: "Hasn't the question of God [...] come to be considered as practically useless? 

Initiation into Christianity has a clear three-part structure, corresponding to the three great questions: God, Jesus Christ, and the Holy Spirit and the Church. And also with the three parts of the Creed. 

Asimiosmo also prefaces them with an extensive introduction, where he explains what it means to believe, to accept the faith. In the prologue, written in 1967, he described the intention of the book as follows: "It aims to help a new understanding of faith as the reality that makes it possible to be authentic human beings in today's world. Dispensing with "a verbiage that can only barely conceal a great spiritual emptiness". 

It was necessary to transmit to those students a living and challenging expression of faith. Not just anything, but that they would see in it the path to the fullness of their lives. This demanded to be very clear about the starting point, the mental status in which the students were, as well as the pathway. That challenge of 1967 is the merit of the book. 

The starting point is that faith is irrelevant for Westerners living on the margins. In former times, faith relied heavily on an attachment to tradition, but that itself makes it obsolete for those who today place their trust in progress.

A theologian today recalls the clown in Kierkegaard's story who came to the village to warn of the danger of fire. They laughed at him and did not expect him to say anything worthwhile. He would have to change his costume, like theology. But besides the fact that it's not easy, wouldn't getting comfortable be getting lost? That is "the unsettling power of unbelief," because objections also affect the Christian, child of his time: what if there is nothing? The interesting thing is that the unbeliever is in a parallel status : what if faith is true? God is essentially invisible. Therefore, faith is "a choice whereby what is not seen [is considered] as the authentically real". It is a decision and a "turning around" or conversion. But it is very demanding, because it is not a vague belief that "something" exists, but that it has intervened in our history: "that man of Palestine"....

He traces the itineraries of modern thought and the successive difficulties of faith, from the positivism of modern science to Marxism. He concludes that believing today means accepting Christian revelation as the foundation of one's own existence. 

For this reason, "the first and last words of the creed - 'I believe' and 'amen' - are intertwined. And it is also "I believe in you," precisely because of the meaning of incarnation and history. I believe in the Logos - reason for everything - incarnate. And that means that in Him (and not in me) I am sustained. This faith also has an ecclesial dimension, because it is believed with the Church and with its expressions, the creeds. 

From entrance, he delves into the word, so as not to work only with a worn-out name, but to notice all that it implies, also in relation to the world and subject. He goes through the history of the revelation to Israel, where God is sample so different from other gods, staff and unique, and all divinization of bread (of goods), of eros or of political power is forbidden. Starting from the scene of the burning bush in the book of Exodus, with the vocation of Moses, he goes through the biblical names of God(El, Elohim, Yahweh) up to the God of the Fathers of Israel and the God of Jesus Christ. With the tremendous force of the Name that suggests that only God truly "is". And the echo of "I am" in the New Testament and in Jesus Christ himself. With that paradoxical double aspect of the absolute solemnity of "I am" and, at the same time, the closeness of a God for Israel, for all men. And at the end, Father. 

From there he jumps to the classical comparison of the God of faith with the God of the philosophers. Christian antiquity knew how to synthesize its knowledge of the biblical God with the reflection of the classical Philosophy on the foundation of the universe. And always, at the same time, Father. This happy meeting illustrated the important role that rational thought - theology - plays in the Christian faith. In modern reflection, the two dimensions remain important: God as the foundation and Logos of the cosmos, and Father, as the horizon of all persons. And from this need for relationship comes a beautiful and broad development of the Trinity, which it is not possible to summarize here without reducing too much. But there is the core topic for the meaning and fulfillment of the human being. 

This second part is divided, in turn, into two parts: the first, I believe in Jesus Christ, his only Son, our Lord; the second, on the statements of the Creed about Jesus Christ: he was born of the Virgin Mary, he suffered..., he rose again... The starting point is "the problem of confessing Jesus today", of confessing, at the same time, the Logos and his incarnation, the latter being always more scandalous: how can the whole reality of the cosmos and of humanity revolve around something that happened at a moment in history? This cannot be fully achieved either from physics or from history. Moreover, the modern era tries to separate Jesus from Christ, dismantling what is supposed to be assembled in history. To dispense with the Son allows to remain only with a generic Father, more acceptable in the interreligious field. And also to remain with a model of Jesus Christ apparently closer.

But Jesus is the Christ and that degree scroll of Messiah (confused in his time) is realized above all on the cross. " Jesus is Christ, he is King insofar as he is crucified", with the kingship of the gift of self, of love. And "in this way he makes love into Logos, into the truth of the human being". topic reinforced by the scene of the final judgment, where the Lord asks his own to see him in the brethren (cf. Mt 25). The identity of Jesus with the Christ of the Cross is also the identity of the Logos with love. He then addresses at length the mystery of the God-man. 

The last part, much shorter, is also subdivided in two. First, it briefly addresses the unity of the last articles of the Creed, around the confession in the Holy Spirit and the Church that He animates. 

Then he dwells a bit more on two "difficult" points for those who heard him then and for those who read him today: the holiness of the Church and the resurrection of the flesh. How can one affirm against historical evidence that the Church is holy? He solves it in an original way. The Church, precisely because she is salvific, is board with what is sin, like Jesus Christ himself. It is not a luminous and transcendent entity. It is incarnated in order to save. " In the Church, holiness begins by enduring and ends by enduring". Those who look only at the organization and not at the sacraments do not understand it. True believers always live by the sacraments, while the organization changes better or worse in history.

As for the final resurrection of the dead, it is a requirement of the totality that is the human being with his bodily dimension. And it is convenient to detach oneself from certain aspects of the ancient Greek duality body/soul, because the Christian faith's conception of the human being is unitary. And its fullness does not consist in a simple survival of the soul, freed from the body, but in a "dialogical immortality", a life and a resurrection founded on the love of God for each person. God's love is what sustains the human personality and resurrection is a saving act of God's love that brings it to its fullness. This he will develop later in his Eschatology.

We return to the remarks in the prologue, which the then Cardinal Ratzinger added in 2000. Especially after 1989, with the fall of communism, "all these projects [...] had to be withdrawn at the moment when faith in politics as the power of salvation broke down". Then, "in the leaden solitude of a world orphaned of God, in its inner boredom, the search for mysticism arose". In experiences, oriental surrogates, etc. And also apparitions. While people "largely pass from the traditional Christian churches. The institution bothers and the dogma also".

This is the novelty compared to the sixties. Part opportunity, part confusion. And it demands again, but in a different way, to show the characteristics of the Christian God, who works in history, with a Son who becomes man, in the face of the syncretistic tendency. And to the blurring of the idea of God, more and more impersonal, in order to make it acceptable not only to other religions, but also to those who do not want to believe.

But the center has not changed: it is always to show Christ, the Son, as the object of our faith (I believe in you), with that double dimension of Logos, the reason for everything, and of love for us, manifested and given on the cross. We need this double dimension to find the meaning of life and our salvation. And since then it is a core topic of Joseph Ratzinger's theology.