Teachings
As pope, one of Benedict's main roles was to teach about the Catholic faith and the solutions to the problems of discerning and living the faith, a role that he could play well as a former head of the Church's Congregation for the Doctrine of the Faith.
After his first homily as pope, Benedict referred to both Jesus Christ and John Paul II. Citing John Paul II's well-known words, "Do not be afraid! Open wide the doors for Christ!", Benedict said:
Are we not perhaps all afraid in some way? If we let Christ enter fully into our lives, if we open ourselves totally to Him, are we not afraid that He might take something away from us? ... And once again the Pope said: No! If we let Christ into our lives, we lose nothing, nothing, absolutely nothing of what makes life free, beautiful, and great. No! Only in this friendship do we experience beauty and liberation. ... When we give ourselves to Him, we receive a hundredfold in return. Yes, open, open wide the doors to Christ – and you will find true life.
"Friendship with Jesus Christ" was a frequent theme of Benedict's preaching. He stressed that on this intimate friendship, "everything depends". He also said: "We are all called to open ourselves to this friendship with God ... speaking to Him as to a friend, the only One who can make the world both good and happy ... That is all we have to do is put ourselves at His disposal ... is an extremely important message. It is a message that helps to overcome what can be considered the great temptation of our time: the claim, that after the Big Bang, God withdrew from history." Thus, in his book Jesus of Nazareth, his main purpose was "to help foster [in the reader] the growth of a living relationship" with Jesus Christ. He took up this theme in his first encyclical Deus caritas est. In his explanation and summary of the encyclical, he stated: "If friendship with God becomes for us something ever more important and decisive, then we will begin to love those whom God loves and who are in need of us. God wants us to be friends of His friends and we can be so, if we are interiorly close to them." Thus, he said that prayer is "urgently needed ... It is time to reaffirm the importance of prayer in the face of the activism and the growing secularism of many Christians engaged in charitable work."
Continuing what he said in the pre-conclave Mass about what he often referred to as the "central problem of our faith today", on 6 June 2005, Benedict also said:
Today, a particularly insidious obstacle to the task of education is the massive presence in our society and culture of that relativism which, recognising nothing as definitive, leaves as the ultimate criterion only the self with its desires. And under the semblance of freedom it becomes a prison for each one, for it separates people from one another, locking each person into his or her own ego.
Benedict said that "a dictatorship of relativism" was the core challenge facing the Church and humanity. At the root of this problem, he said, is Immanuel Kant's "self-limitation of reason". This, he said, is contradictory to the modern acclamation of science whose excellence is based on the power of reason to know the truth. He said that this self-amputation of reason leads to pathologies of religion such as terrorism and pathologies of science such as ecological disasters. Benedict traced the failed revolutions and violent ideologies of the 20th century to a conversion of partial points of view into absolute guides. He said "Absolutizing what is not absolute but relative is called totalitarianism."
In the discussion with secularism and rationalism, one of Benedict's basic ideas can be found in his address on the "Crisis of Culture" in the West, a day before Pope John Paul II died, when he referred to Christianity as the "religion of the Logos" (the Greek for "word", "reason", "meaning", or "intelligence"). He said:
From the beginning, Christianity has understood itself as the religion of the Logos, as the religion according to reason ... It has always defined men, all men without distinction, as creatures and images of God, proclaiming for them ... the same dignity. In this connection, the Enlightenment is of Christian origin and it is no accident that it was born precisely and exclusively in the realm of the Christian faith. ... It was and is the merit of the Enlightenment to have again proposed these original values of Christianity and of having given back to reason its own voice ... Today, this should be precisely [Christianity's] philosophical strength, in so far as the problem is whether the world comes from the irrational, and reason is not other than a 'sub-product,' on occasion even harmful of its development – or whether the world comes from reason, and is, as a consequence, its criterion and goal ... In the so necessary dialogue between secularists and Catholics, we Christians must be very careful to remain faithful to this fundamental line: to live a faith that comes from the Logos, from creative reason, and that, because of this, is also open to all that is truly rational.
Benedict also emphasised that "Only creative reason, which in the crucified God is manifested as love, can really show us the way."
Benedict wrote three encyclicals: Deus caritas est (Latin for "God is Love"), Spe salvi ("Saved by Hope"), and Caritas in veritate ("Love in Truth").
In his first encyclical, Deus caritas est, he said that a human being, created in the image of God who is love, can practise love: to give himself to God and others (agape) by receiving and experiencing God's love in contemplation. This life of love, according to him, is the life of the saints such as Teresa of Calcutta and the Blessed Virgin Mary, and is the direction Christians take when they believe that God loves them in Jesus Christ. The encyclical contains almost 16,000 words in 42 paragraphs. The first half is said to have been written by Benedict in German, his first language, in the summer of 2005; the second half is derived from uncompleted writings left by his predecessor, Pope John Paul II. The document was signed by Benedict on Christmas Day, 25 December 2005. The encyclical was promulgated a month later in Latin and was translated into English, French, German, Italian, Polish, Portuguese, and Spanish. It is the first encyclical to be published since the Vatican decided to assert copyright in the official writings of the pope.
Benedict's second encyclical titled Spe Salvi ("Saved by Hope"), about the virtue of hope, was released on 30 November 2007.
His third encyclical titled Caritas in veritate ("Love in Truth" or "Charity in Truth"), was signed on 29 June 2009 (the Feast of Sts. Peter and Paul) and released on 7 July 2009. In it, the Pope continued the Church's teachings on social justice. He condemned the prevalent economic system "where the pernicious effects of sin are evident", and called on people to rediscover ethics in business and economic relations.
At the time of his resignation, Benedict had completed a draft of a fourth encyclical entitled Lumen fidei ("The Light of Faith"), intended to accompany his first two encyclicals to complete a trilogy on the three theological virtues of faith, hope, and love. Benedict's successor, Francis, completed and published Lumen Fidei in June 2013, four months after Benedict's retirement and Francis's succession. Although the encyclical is officially the work of Francis, paragraph 7 of the encyclical explicitly expresses Francis's debt to Benedict: "These considerations on faith—in continuity with all that the Church's magisterium has pronounced on this theological virtue—are meant to supplement what Benedict XVI had written in his encyclical letters on charity and hope. He himself had almost completed a first draft of an encyclical on faith. For this I am deeply grateful to him, and as his brother in Christ I have taken up his fine work and added a few contributions of my own."
Sacramentum caritatis (The Sacrament of Charity), signed 22 February 2007, was released in Latin, Italian, English, French, German, Portuguese, Spanish, and Polish. It was made available in various languages on 13 March 2007 in Rome. The English edition of Libera Editrice Vaticana is 158 pages. This apostolic exhortation "seeks to take up the richness and variety of the reflections and proposals which emerged from the Ordinary General Assembly of the Synod of Bishops" which was held in 2006.
On 7 July 2007, Benedict issued the motu proprio Summorum Pontificum, declaring that upon "the request of the faithful", the celebration of Mass according to the Missal of 1962 (of the Tridentine Mass), was to be more easily permitted. Stable groups who previously had to petition their bishop to have a Tridentine Mass may now merely request permission from their local priest. While Summorum Pontificum directs that pastors should provide the Tridentine Mass upon the requests of the faithful, it also allows for any qualified priest to offer private celebrations of the Tridentine Mass, to which the faithful may be admitted if they wish. For regularly scheduled public celebrations of the Tridentine Mass, the permission of the priest in charge of the church is required.
In an accompanying letter, the Pope outlined his position concerning questions about the new guidelines. As there were fears that the move would entail a reversal of the Second Vatican Council, Benedict emphasised that the Tridentine Mass would not detract from the council and that the Mass of Paul VI would still be the norm and priests were not permitted to refuse to say the Mass in that form. He pointed out that the use of Tridentine Mass "was never juridically abrogated and, consequently, in principle, was always permitted." The letter also decried "deformations of the liturgy ... because in many places celebrations were not faithful to the prescriptions of the new Missal" as the Second Vatican Council was wrongly seen "as authorising or even requiring creativity", mentioning his own experience.
The Pope considered that allowing the Tridentine Mass to those who request it was a means to prevent or heal schism, stating that, on occasions in history, "not enough was done by the Church's leaders to maintain or regain reconciliation and unity" and that this "imposes an obligation on us today: to make every effort to enable for all those who truly desire unity to remain in that unity or to attain it anew." Cardinal Darío Castrillón Hoyos, the president of the Pontifical Commission established to facilitate full ecclesial communion of those associated with that Society, stated that the decree "opened the door for their return". Bishop Bernard Fellay, superior general of the SSPX, expressed "deep gratitude to the Sovereign Pontiff for this great spiritual benefit".
In July 2021, Pope Francis issued the apostolic letter titled Traditionis custodes, which substantially reversed the decision of Benedict XVI in Summorum Pontificum and imposed new and broad restrictions on the use of the Traditional Latin Mass. The decision was controversial and widely criticized by conservative and traditionalist Catholics as lacking in charity and an attack on those attached to the liturgical patrimony of the Church.
Near the end of June 2007, the Congregation for the Doctrine of the Faith issued a document approved by Benedict XVI "because some contemporary theological interpretations of Vatican II's ecumenical intent had been 'erroneous or ambiguous' and had prompted confusion and doubt." The document has been seen as restating "key sections of a 2000 text the pope wrote when he was prefect of the congregation, Dominus Iesus."
Benedict condemned excessive consumerism, especially among youth. He stated in December 2007 that "[A]dolescents, youths and even children are easy victims of the corruption of love, deceived by unscrupulous adults who, lying to themselves and to them, draw them into the dead-end streets of consumerism." In June 2009, he blamed outsourcing for the greater availability of consumer goods which lead to the downsizing of social security systems.