By Cindy Wooden Catholic News Service ROME (CNS) -- Politicians who want to act as if God did not exist and as if there was no such thing as objective moral truths are bound to fail in their efforts to promote the common good, said the head of the Congregation for the Doctrine of the Faith. "The politics we have today in Europe and North America without ethical foundations, without a reference to God, cannot resolve our problems, even those of the market and money," said Archbishop Gerhard L. Muller, prefect of the Congregation for the Doctrine of the Faith. The archbishop, coordinator of the project to publish the complete works of Joseph Ratzinger-Pope Benedict XVI, said one of the key teachings of the pope is the importance of faith and reason going hand in hand. Speaking Jan. 11 at a Vatican bookstore in downtown Rome, Archbishop Muller said, "Faith and reason are like two people who love each other deeply, who cannot live without each other, and who were intimately made for one another, so much so that they cannot be considered separate from one another and cannot reach their goals separately." He quoted Pope Benedict XVI's speech to diplomats Jan. 7: "It is precisely man's forgetfulness of God, and his failure to give him glory, which gives rise to violence. Indeed, once we no longer make reference to an objective and transcendent truth, how is it possible to achieve an authentic dialogue?" Archbishop Muller said that in the current run-up to Italian elections he has heard that some politicians want the Catholic Church to "talk about love, charity and mercy of God," but not insist that the truths it preaches be upheld. "But where is love without truth?" the archbishop asked. The archbishop made his comments during a short presentation of his new book in Italian, "Ampliare L'Orizzonte della Ragione. Per una Lettura di Joseph Ratzinger-Benedetto XVI," ("Broadening the Horizons of Reason: Reading Joseph Ratzinger-Benedict XVI"). In the book, Archbishop Muller highlights: the importance Pope Benedict gives to the need for faith and reason to support and purify one another; the pope's insistence that Christianity is primarily about a relationship with Jesus Christ and not simply the acceptance of rules and doctrines; and the key role that studying the life and work of St. Augustine has had both on the pope's theology and on his ministry. During the presentation, the archbishop also underscored how deeply Pope Benedict believes the liturgy, especially the Mass, is central to the life and future of the church. The first volume of the pope's complete works in German to be translated into Italian was Volume 11 on the liturgy; the decision to begin with that, Archbishop Muller said, was "the express will of the Holy Father, because he said it is a decisive question for the church today and for its future." "The liturgy is not just a memorial, but an encounter with God ... with Jesus Christ present among us," the archbishop said. Pope Benedict believes the pre-Vatican II liturgy needed to be reformed, he said. The pope's position is not that of the traditionalist Society of St. Pius X, "with whom we are in discussions," but the pope also has taken pains to reverse the "many abuses" that took place with the reformed liturgy after the Second Vatican Council. "The liturgy is very important for the church, and we must avoid these extremes of preserving forms at all costs and doing whatever one wants," he said. Archbishop Muller said Catholics can rightly be proud of having such a great theologian as their pope. In fact, he said, he would list the pope -- along with the 18th-century Pope Benedict XIV and the fifth-century St. Leo the Great -- as the greatest theologian-popes. At the same time, "the language of Benedict XVI is very simple," he said. "He has never used language to hermetically seal off his theology from people's real lives." PHOTO: Archbishop Gerhard L. Muller, prefect of the Congregation for the Doctrine of the Faith, attends the presentation of his book on Pope Benedict XVI's writings in Rome Jan. 11. (CNS photo/Paul Haring)