16. The celebration of Mass, as the action of Christ and of the People of God arrayed hierarchically, is the center of the whole of Christian life for the Church both universal and local, as well as for each of the faithful individually. For in it is found the high point both of the action by which God sanctifies the world in Christ and of the worship that the human race offers to the Father, adoring him through Christ, the Son of God, in the Holy Spirit. In it, moreover, during the course of the year, the mysteries of redemption are celebrated so as to be in some way made present. As to the other sacred actions and all the activities of the Christian life, these are bound up with it, flow from it, and are ordered to it.
17. It is, therefore, of the greatest importance that the celebration of the Mass or the Lord’s Supper be so ordered that the sacred ministers and the faithful taking part in it, according to the state proper to each, may draw from it more abundantly those fruits, to obtain which, Christ the Lord instituted the Eucharistic Sacrifice of his Body and Blood and entrusted it as the memorial of his Passion and Resurrection to the Church, his beloved Bride.
18. This will fittingly come about if, with due regard for the nature and other circumstances of each liturgical assembly, the entire celebration is arranged in such a way that it leads to a conscious, active, and full participation of the faithful, namely in body and in mind, a participation fervent with faith, hope, and charity, of the sort which is desired by the Church and which is required by the very nature of the celebration and to which the Christian people have a right and duty in virtue of their Baptism.
95. 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. They should, moreover, take care to show this by their deep religious sense and their charity toward brothers and sisters who participate with them in the same celebration.
They are consequently to avoid any appearance of singularity or division, keeping in mind that they have only one Father in heaven and that hence are all brothers or sisters one to the other.
96. Moreover, they are to form one body, whether in hearing the Word of God, or in taking part in the prayers and in the singing, or above all by the common offering of the Sacrifice and by participating together at the Lord’s table. This unity is beautifully apparent from the gestures and bodily postures observed together by the faithful.
97. The faithful, moreover, should not refuse to serve the People of God in gladness whenever they are asked to perform some particular service or function in the celebration.