On Dec. 4, 1963, Sacrosanctum Concilium, the Constitution on the Sacred Liturgy — the first of four constitutions resulting from the Second Vatican Council — was promulgated by Pope Paul VI. The text launched the liturgical reform implemented at the end of the council’s work.

The other conciliar constitutions were Lumen Gentium, Dei Verbum and Gaudium et Spes.

The guidelines of Sacrosanctum Concilium called for a “simplification” of the liturgy and introduced vernacular languages in the context of celebrations. 

At one of his last general audiences, Pope Benedict XVI — who as a young professor had participated in the Second Vatican Council as an assistant to Cardinal Joseph Frings of Cologne — explained the deep meaning of the conciliar constitution.

Dedicating the council’s first constitution to the liturgy, said Pope Benedict, was important because it demonstrated “the primacy of God.”

“Some have made the criticism that the Council spoke of many things, but not of God,” he said. “It did speak of God! And this was the first thing that it did, that substantial speaking of God and opening up all the people, the whole of God’s holy people, to the adoration of God, in the common celebration of the liturgy of the Body and Blood of Christ. In this sense, over and above the practical factors that advised against beginning straight away with controversial topics, it was, let us say, truly an act of Providence that at the beginning of the Council was the liturgy, God, adoration.”

First and foremost among the essential ideas, Benedict XVI continued, there was “the Paschal Mystery as the center of what it is to be Christian — and therefore of the Christian life, the Christian year, the Christian seasons, expressed in Eastertide and on Sunday, which is always the day of the Resurrection. Again and again, we begin our time with the Resurrection, our encounter with the Risen One, and from that encounter with the Risen One we go out into the world.

“In this sense, it is a pity that these days Sunday has been transformed into the weekend, although it is actually the first day. It is the beginning. We must remind ourselves of this: it is the beginning, the beginning of creation and the beginning of re-creation in the Church. It is an encounter with the Creator and with the Risen Christ. This dual content of Sunday is important — it is the first day, that is, the feast of creation. We are standing on the foundation of creation. We believe in God the Creator, and it is an encounter with the Risen One who renews creation — his true purpose is to create a world that is a response to the love of God.”

According to Pope Benedict, Sacrosanctum Concilium also reaffirmed the principle of “intelligibility, instead of being locked up in an unknown language that is no longer spoken, and also active participation.”

“Unfortunately,” he continued, “these principles have also been misunderstood. Intelligibility does not mean banality, because the great texts of the liturgy — even when, thanks be to God, they are spoken in our mother tongue — are not easily intelligible, they demand ongoing formation on the part of the Christian if he is to grow and enter ever more deeply into the mystery and so arrive at understanding.

“And also the word of God — when I think of the daily sequence of Old Testament readings, and of the Pauline Epistles and the Gospels — who could say that he understands immediately, simply because the language is his own? Only ongoing formation of hearts and minds can truly create intelligibility and participation that is something more than external activity, but rather the entry of the person, of my being, into the communion of the Church and thus into communion with Christ.”

In a 2010 letter citing Sacrosanctum Concilium, Pope Benedict exhorted the Italian bishops “to appreciate the Liturgy as a perennial source of education in the good life of the Gospel. It introduces the person into the encounter with Jesus Christ, who with words and deeds constantly builds the Church, forming her in the depths of listening, of brotherhood and of mission. The rites are eloquent by virtue of their intrinsic rationality and teach a conscious, active and fruitful participation.”