More about GIRM - the worshiping assembly at Mass

The celebration of Mass is a corporate act, an act of the whole assembly gathered for worship. All the particular ministries serve this corporate function (GIRM #27). In the Mass, the Church is joined to the action of Christ, "the high point of the work that in Christ God accomplishes to sanctify us and the high point of the worship that the human race offers to the Father, whom we adore through Christ, the Son of God, in the Holy Spirit" (#16). We are joined to this divine action through baptism, which incorporates us into the risen Christ. This action, which lies at the center of the whole Christian life (#16) is not initiated by us but by God acting in and through the Church as the body of the risen Christ. It becomes our action only to the extent that we give ourselves to this mystery of redemptive worship. The liturgy is designed to bring about in all those who make up the worshiping assembly "a participation in body and spirit that is conscious, active, full, and motivated by faith, hope, and charity" (#18). To the extent that we are able to participate in this way, the work of redemption becomes personally effective for each of us. By such participation, the General Instruction says, we make the actions and prayers of the liturgy our own; we enter more fully into our personal communion with Christ’s redeeming act and perfect worship (see #54, 55, etc.).

In the celebration of Mass the faithful are a holy people, a chosen people, a royal priesthood: they give thanks to God and offer the Victim not only through the hands of the priest but also together with him and learn to offer themselves. They should endeavor to make this clear by their deep sense of reverence for God and their charity toward brothers and sisters who share with them in the celebration (#95). They should become one body, whether by hearing the word of God, or joining in prayers and liturgical song, or above all by offering the sacrifice together and sharing together in the Lord’s Table (#96).

Because the whole liturgy is a corporate act of the gathered assembly (GIRM #34; Catechism of the Catholic Church #1144), there are certain parts of the Mass that are to be done by the whole assembly, the congregation of the faithful and all the ministers, in order to express the corporate nature of this act. Through these actions, the entire congregation of the faithful joins itself to Christ in acknowledging the great things that God has done and in offering the sacrifice (#78). These acts include: