Why do Catholics go to Mass?
The celebration of Mass is an act of the whole assembly gathered for worship. In the Mass, the Church is joined to the action of Christ. 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 of Christian life” (General Instruction of the Roman Missal [GIRM], no. 16), is initiated not by us but by God acting in and through the Church as the Body of the risen Christ.
The Liturgy is designed to bring about in all those who make up the worshiping assembly a “participation of the faithful, namely in body and in mind, a participation fervent with faith, hope, and charity” (GIRM, no. 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 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. “In the celebration of Mass the faithful form a holy people, a people of God’s own possession and a royal Priesthood, so that they may give thanks to God and offer the unblemished sacrificial Victim not only by means of the hands of the Priest but also together with him and so that they may learn to offer their very selves.