This text is the result of the forty years’ experience Luigi Giussani had as a religion teacher, first at the Berchet High School in Milan, then at the Catholic University of the Sacred Heart.  It is a textbook for teaching Catholic religion, adopted in Italian secondary schools since 1999 (first edition).
This volume synthetically reproposes the contents developed in the volumes of the PerCorso; these are offered to high school students in a version that is accompanied by an extensive iconographic apparatus, fact sheets and documents, edited by Professor Gianni Mereghetti, in accordance with the ministerial programs agreed upon with the Italian Bishops’ Conference.
It is an existential approach to the religious phenomenon that begins with the discovery of a religious sense and continues in the encounter with Christ and His Church.

The Religious Sense

The religious sense is that set of questions that constitute the stuff of what reason is made, “Why, in the end, is life worth living? What is the meaning of the reality that surrounds me?” Paying attention to one’s own “I”-in-action” is the only effective way to know this sort of phenomenon. We will then realize that alongside the “carnal” reality there is a “spiritual” one, consisting of questions about the ultimate sense of life that cannot be rooted out. In the face of these questions, an individual is continually tempted to assume unreasonable positions that empty the questions and reduce them to feeling or willpower. This reduction results in a break with the past, solitude and loss of freedom. In fact, we can only be truly free if we admit the existence of something within us that derives not from our biological and historical antecedents but is direct relationship with the infinite.
The religious sense continually emerges in the impact with reality. Those people who pay attention to their own experience first feel a sense of awe in front of a reality that imposes itself and they did not themselves make. At a later time, as they become aware of their own “I,” they realize that they are not being made by themselves, that they depend on another, whom religious tradition calls “God.”
Human freedom is continually involved in the adventure of interpreting a reality that manifests itself as a sign, but in order for freedom to be maintained in a positive attitude, education is necessary. All those who take their humanity seriously will find themselves in a dizzying position, longing to penetrate the Mystery whose face they cannot see and in the constant risk of reducing the total meaning to an idol, that is, to something finite and comprehensible.
But, at the edge of this passionate and hard-won consciousness of existence, a cry of the truest humanity breaks out as a begging, a demand for meaning to reveal itself—it is the hypothesis of revelation.

At the Origin of the Christian Claim

Throughout the ages human beings have been striving to find the Mystery and, not being able to reach it, have realized that the only decisive help could come from the Mystery itself.
Within the freedom of attempts that are made, a religion commits a crime when it claims, “I am the religion.” This is the Christian claim. It is based on the hypothesis that the presence that makes all things penetrated the fabric of history and became incarnated in a human fact. We can then only ask ourselves: did it or did it not happen? A fact like this would radically overturn the religious method because, in front of it, recognizing it and adhering to it would be enough.
The Mystery chose to become a man and be met in the same way as you would come across a friend. In this encounter a profound correspondence happens between your human expectation and the event before you; it is precisely this exceptionality that enabled John and Andrew to cry out, “We have found the Messiah.” By staying with him, Jesus’ friends discovered his incomparable traits: an unassailable intelligence, an absolute power over nature, a gaze that could read the secret of everyone’s heart, a capacity to be moved by his endless emotion over the destiny of every person. By virtue of this correspondence, they were led from the experience of encountering His humanity to the question about His divinity, “Who are you?” Jesus answered this question through a slow pedagogy, gradually adding elements that suggested the answer, up to the explicit revelation of his divine nature.
The greatest sign of the fact that Jesus is God is the consonance between his conception of life and human expectation—for only God can unveil and fulfill the whole breadth of human nature. Original sin would make man incapable of having a fulfilled relationship with God and thus with himself. It is the presence of Jesus that continually sustains the freedom of the person; a Christian is thus someone who in the certainty of the companionship of Christ (faith) walks full of hope and capable of a new affection for everything (charity).
Two thousand years later, the original nature of the method of the Incarnation remains identical, forcing anyone to take a stand: God saves man through man, the encounter with a living human reality.

The Heart of the Church Problem

When addressing the problem of the Church, the question is, “How can someone who has not directly known Christ evaluate whether He is truly the son of God?” There are three possible methods. The first is to proceed with a historical-rationalistic analysis to gather all the data; the second is to seek a direct inner relationship with God, as is the case in Protestantism. These two methods reduce the Christian fact to subjectivism, while the third, the Christian-Orthodox one, remaining faithful to the dynamic that occurred two thousand years ago, affirms that a human encounter is necessary to know Christ.
Today, a lack of attunement with Christian words makes them extraneous to mankind. While the Middle Ages were characterized by easily conceiving God as a present and crucial factor in every aspect of life, a process of disarticulation of this unitary religious mentality developed in later centuries. Humanism, Renaissance and rationalism exalted human capacity to the bitter end, conceived in an abstract way, thus leading to scientism and limitless confidence in scientific progress. It is easy for people today to acknowledge God as long as nobody claims He has something to do with human reality—this is the secularist culture, for which life is conceived and lived as if God were not there.
The Church stands in history as the place of the relationship with the living Christ. For the beginning of the Church is a group of friends held together by the presence of the risen Christ. There are three constituent factors of this phenomenon.
It is a community, a sociologically identifiable reality (Ecclesia Dei).
Secondly, the first Christians were aware that everything exceptional that happened in them was not the result of their own adherence but the mysterious gift of the Spirit, of a “Strength from on High” that had invested them.
Finally, the Christian fact initiates a new type of life, described in the New Testament by the term koinonia (communion), which denotes a group of people who have something in common. The first Christians jointly possessed the reason for living, Christ.
The Church’s claim to be the vehicle of the divine through human reality generates a disproportion—a very fragile humanity is destined to reveal the invincibility of a Presence that uses us but comes not from us. Moreover, God communicates Himself by means of the environment and the historical-cultural era, so the Church always shows the signs of the particular era in which it operates, while it conserves the truth in its entirety.
The Church has the same purpose in the world and in history as Jesus—to educate man to a clear consciousness and a correct attitude in the face of destiny. This occurs firstly through the communication of truth, which is expressed by the ordinary and extraordinary magisterium of the bishops and the Pope, and secondly through the communication of a divine reality. This divine reality involves man’s being and transforms him into a new creature through the action of sanctifying grace; such grace is communicated by means of concrete gestures, the sacraments, which prolong in history the signs by which Christ communicated Himself.
How can we be certain that the Church is truly the prolongation of Christ in time and space? There are four “fruits” that show the divine value of the Church and its continued effectiveness in history.
Unity, that is, a simplicity uniting our feeling and judgment of life. This is possible because the principle behind our judgment is the one unequivocal Presence.
Holiness, not understood as separation from ordinary, everyday life, but as the prerogative of the self-fulfilled individual, who lives and acts in the awareness of the ultimate motivation for his action.
Catholicity is a dimension of the Church, the expression of its pertinence to human matters and all the forms they take. 
Finally, apostolicity, according to which the Church affirms itself as the only authority to be the custodian of a tradition of values and realities deriving from the apostles and continuing in the Pope and his bishops.

Appendix, Methodological Issues

To know ourselves and reality, and thus also the phenomena that have been discussed, three methodological premises need to be put forward. The first is that of realism, that is, the awareness that the method of any research comes not from a pre-established scheme but is imposed by the object. The second premise that is needed is our being faithful to our own nature, our own reasonableness, that is, our capacity to grasp and affirm reality according to the totality of its factors. Finally, there is a need for morality, our willingness to love the truth more than we love our own images and thoughts.