Why the liturgy?
1066 In the Symbol of the faith the Church confesses the mystery of the Holy Trinity and of the plan of God's "good pleasure" for all creation: the Father accomplishes the "mystery of his will" by giving his beloved Son and his Holy Spirit for the salvation of the world and for the glory of his name.1
Such is the mystery of Christ, revealed and fulfilled in history according to the wisely ordered plan that St. Paul calls the "plan of the mystery"2 and the patristic tradition will call the "economy of the Word incarnate" or the "economy of salvation."
1067 "The wonderful works of God among the people of the Old Testament were but a prelude to the work of Christ the Lord in redeeming mankind and giving perfect glory to God. He accomplished this work principally by the Paschal mystery of his blessed Passion, Resurrection from the dead, and glorious Ascension, whereby 'dying he destroyed our death, rising he restored our life.' For it was from the side of Christ as he slept the sleep of death upon the cross that there came forth 'the wondrous sacrament of the whole Church."'3 For this reason, the Church celebrates in the liturgy above all the Paschal mystery by which Christ accomplished the work of our salvation.
1068 It is this mystery of Christ that the Church proclaims and celebrates in her liturgy so that the faithful may live from it and bear witness to it in the world:
What does the word liturgy mean?
1069 The word "liturgy" originally meant a "public work" or a "service in the name of/on behalf of the people." In Christian tradition it means the participation of the People of God in "the work of God."5 Through the liturgy Christ, our redeemer and high priest, continues the work of our redemption in, with, and through his Church.
1070 In the New Testament the word "liturgy" refers not only to the celebration of divine worship but also to the proclamation of the Gospel and to active charity.6 In all of these situations it is a question of the service of God and neighbor. In a liturgical celebration the Church is servant in the image of her Lord, the one "leitourgos";7 she shares in Christ's priesthood (worship), which is both prophetic (proclamation) and kingly (service of charity):
Liturgy as source of life
1071 As the work of Christ liturgy is also an action of his Church. It makes the Church present and manifests her as the visible sign of the communion in Christ between God and men. It engages the faithful in the new life of the community and involves the "conscious, active, and fruitful participation" of everyone.9
1072 "The sacred liturgy does not exhaust the entire activity of the Church":10 it must be preceded by evangelization, faith, and conversion. It can then produce its fruits in the lives of the faithful: new life in the Spirit, involvement in the mission of the Church, and service to her unity.
Prayer and liturgy
1073 The liturgy is also a participation in Christ's own prayer addressed to the Father in the Holy Spirit. In the liturgy, all Christian prayer finds its source and goal. Through the liturgy the inner man is rooted and grounded in "the great love with which [the Father] loved us" in his beloved Son.11 It is the same "marvelous work of God" that is lived and internalized by all prayer, "at all times in the Spirit."12
Catechesis and liturgy
1074 "The liturgy is the summit toward which the activity of the Church is directed; it is also the font from which all her power flows."13 It is therefore the privileged place for catechizing the People of God. "Catechesis is intrinsically linked with the whole of liturgical and sacramental activity, for it is in the sacraments, especially in the Eucharist, that Christ Jesus works in fullness for the transformation of men."14
1075 Liturgical catechesis aims to initiate people into the mystery of Christ ( It is "mystagogy." ) by proceeding from the visible to the invisible, from the sign to the thing signified, from the "sacraments" to the "mysteries." Such catechesis is to be presented by local and regional catechisms. This Catechism, which aims to serve the whole Church in all the diversity of her rites and cultures,15 will present what is fundamental and common to the whole Church in the liturgy as mystery and as celebration (Section One), and then the seven sacraments and the sacramentals (Section Two).
1 Eph 1:9.
2 Eph 3:9; cf. 3:4.
3 SC 5 § 2; cf. St. Augustine, En. in Ps. 138,2:PL 37,1784-1785.
4 SC 2.
5 Cf. Jn 17:4.
6 Cf. Lk 1:23; Acts 13:2; Rom 15:16,27; 2 Cor 9:12; Phil 2:14-17,25,30.
7 Cf. Heb 8:2,6.
8 SC 7 § 2-3.
9 SC 11.
10 SC 9.
11 Eph 2:4; 3:16-17.
12 Eph 6:18.
13 SC 10.
14 John Paul II, CT 23.
15 Cf. SC 3-4.