Here are my contributions to the section on Teachings in the article on Benedict XVI in Wikipedia.
"Friendship with Jesus Christ"
According to commentators, during the Inaugural Mass, the core of the Pope's message, the most moving and famous part, is found in the last paragraph of his homily where he referred to both Jesus Christ and John Paul II. After referring to John Paul II's well-known words, "Do not be afraid! Open wide the doors for Christ!", Benedict XVI 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" is a frequent theme of his preaching. He stressed that on this intimate friendship, "everything depends." He has 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 personal 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."
"Dictatorship of Relativism"
Continuing what he said in the pre-conclave Mass about what he has often referred to as the "central problem of our faith today", on 6 June 2005 Pope 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.”
He said that "a dictatorship of relativism" was the core challenge facing the church and humanity. At the root of this problem, he said, is 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 twentieth 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 an address to a conference of the Diocese of Rome held at the basilica of St. John Lateran 6 June 2005, Benedict remarked on the issues of same sex marriage and abortion:
The various forms of the dissolution of matrimony today, like free unions, trial marriages and going up to pseudo-matrimonies by people of the same sex, are rather expressions of an anarchic freedom that wrongly passes for true freedom of man...from here it becomes all the more clear how contrary it is to human love, to the profound vocation of man and woman, to systematically close their union to the gift of life, and even worse to suppress or tamper with the life that is born.
Christianity as religion according to reason
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."
Encyclicals: Love and hope
Pope Benedict has to date written 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, "God is love", he said that a human being, created in the image of God who is love, is able to practice love: to give himself to God and others (agape), by receiving and experiencing God's love in contemplation (eros). 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.