To be a Christian is a vocation (a call) to love and truth. If every person has this call, the Christian must commit himself to God to serve the material and spiritual needs of all the people of the world, beginning with those closest to him (his family, his friends).

The encyclical Caritas in veritate, where the term "vocation" (call) appears 25 times, states:
"All men and women perceive the interior impulse to love authentically; love and truth never abandon them completely, because they are the vocation that God has placed in the heart and mind of every human being." This universal vocation to love and truth is manifested by Jesus Christ, who frees it from human limitations and makes it fully possible.

In the measure of their response to this call," the encyclical explains, "men and women, as recipients of God's love, become subjects of charity, called to make themselves instruments of grace in order to spread God's charity and to weave networks of charity".

Since every call awaits a response, what are the conditions for responding to this "vocation to the human development "? The encyclical Caritas in veritate points out three main conditions: freedom, truth and charity.

a) Freedom is always linked to responsibility, a word that comes from responding. And every Christian, as well as Structures and social and ecclesial institutions, must respond to this call - from God, from the human being himself and from those in need.

b) To respond to the human development with truth means "promote to all men and to the whole man". In other words: to be concerned for everyone, with a spirit of solidarity and a universal heart, and to attend to all the real needs of others, those of the body and those of the spirit. To this purpose the Gospel is fundamental, because it teaches to know and respect the unconditional value of the human person. Christ reveals man to man himself," the Second Vatican Council points out, "and so he reveals to him sample that his value is great in the eyes of God. sample "God's great yes" to all his desires. 

From this the Pope deduces that only by opening oneself to God can man be happy and fully realized: "Precisely because God pronounces the greatest 'yes' to man, man cannot fail to open himself to the divine vocation in order to realize - above all - his own development" and to contribute to the development of others.

c) Finally, "the vision of development as a vocation implies that its center is charity". The causes of underdevelopment - the encyclical reads - are not primarily material, but lie first of all "in the will, which often neglects the duties of solidarity". Secondly, in thought, which does not always know how to adequately orient the will (hence the need for a "new humanism"). And, above all, the cause lies in "the lack of fraternity among men and among peoples".   

Now," Benedict XVI asks himself, "can people achieve this fraternity on their own, especially in our age of globalization? And he answers that no, because fraternity is born of God the Father, who first loved us and taught us through his Son what fraternal charity is. Hence, he adds, the vocation to development requires today the urgency of the charity of Christ.

Only the urgency of Christ's charity allows us to respond to the concrete and costly aspects of this call. Such is the intervention in public, cultural and political life, each according to his condition. "Every Christian is called to this charity, according to his vocation and his possibilities of influencing the polis." Another aspect is the care and responsibility for nature; and, before that, the respectful care of each person in the family, in the business, in the university, knowing that they are servants and not owners. To respond to this vocation requires the work and the technique that comes from it. In any case, Benedict XVI proclaims the need to form "upright men... who feel strongly in their conscience the call to the common good".

It is important to emphasize that this vocation is not something we have given ourselves, but comes from God. Therefore, first and foremost, and continually, we must welcome God into our lives, allow him to enter freely and follow him with all fidelity and enthusiasm. The time has come - especially for young people and even more so for university students - to commit ourselves to God and to others. For "only if we think that we have been called individually and as a community to be part of God's family as his children, will we be able to forge new thinking and draw new energies at the service of an integral and true humanism".