Celebration

Christ’s Work in the Liturgy
"Accordingly, just as Christ was sent by the Father so also he sent the apostles, filled with the Holy Spirit. This he did so that they might preach the Gospel to every creature and proclaim that the Son of God by his death and resurrection had freed us from the power of Satan and from death and brought us into the Kingdom of his Father. But he also willed that the work of salvation which they preached should be set in train through the sacrifice and sacraments, around which the entire liturgical life revolves." [Sacrosanctum Concilium 6] 1086

The Holy Spirit prepares for the reception of Christ
In the sacramental economy the Holy Spirit fulfills what was prefigured in the Old Covenant. Since Christ's Church was "prepared in marvellous fashion in the history of the people of Israel and in the Old Covenant," [LG 2] the Church's liturgy has retained certain elements of the worship of the Old Covenant as integral and irreplaceable, adopting them as her own:

• notably, reading the Old Testament;
• praying the Psalms;
• above all, recalling the saving events and significant realities which have found their fulfillment in the mystery of Christ (promise and covenant, Exodus and Passover, kingdom and temple, exile and return). 1093

The Holy Spirit makes present the mystery of Christ

The Sacraments of Eternal Life
The Church celebrates the mystery of her Lord "until he comes," when God will be "everything to everyone." [1 Cor 11:26; 15:28] Since the apostolic age the liturgy has been drawn toward its goal by the Spirit's groaning in the Church: Marana tha! [1 Cor 16:22] The liturgy thus shares in Jesus' desire: "I have earnestly desired to eat this Passover with you . . . until it is fulfilled in the kingdom of God." [Lk 22:15] In the sacraments of Christ the Church already receives the guarantee of her inheritance and even now shares in everlasting life, while "awaiting our blessed hope, the appearing of the glory of our great God and Savior Christ Jesus." [Titus 2:13] The "Spirit and the Bride say, 'Come . . . Come, Lord Jesus!"' [Rev 22:17, 20]

St. Thomas sums up the various aspects of sacramental signs: "Therefore a sacrament is a sign that commemorates what precedes it- Christ's Passion; demonstrates what is accomplished in us through Christ's Passion - grace; and prefigures what that Passion pledges to us - future glory. [St. Thomas Aquinas, STh III, 60, 3] 1130

Words and actions
A sacramental celebration is a meeting of God's children with their Father, in Christ and the Holy Spirit; this meeting takes the form of a dialogue, through actions and words. Admittedly, the symbolic actions are already a language, but the Word of God and the response of faith have to accompany and give life to them, so that the seed of the Kingdom can bear its fruit in good soil. The liturgical actions signify what the Word of God expresses: both his free initiative and his people's response of faith. 1153

Liturgical seasons
From the time of the Mosaic law, the People of God have observed fixed feasts, beginning with Passover, to commemorate the astonishing actions of the Savior God, to give him thanks for them, to perpetuate their remembrance, and to teach new generations to conform their conduct to them. In the age of the Church, between the Passover of Christ already accomplished once for all, and its consummation in the kingdom of God, the liturgy celebrated on fixed days bears the imprint of the newness of the mystery of Christ. 1164

The liturgical year
Beginning with the Easter Triduum as its source of light, the new age of the Resurrection fills the whole liturgical year with its brilliance. Gradually, on either side of this source, the year is transfigured by the liturgy. It really is a "year of the Lord's favor." [Lk 4:19] The economy of salvation is at work within the framework of time, but since its fulfillment in the Passover of Jesus and the outpouring of the Holy Spirit, the culmination of history is anticipated "as a foretaste," and the kingdom of God enters into our time. 1168

The liturgy is the work of the whole Christ, head and body. Our high priest celebrates it unceasingly in the heavenly liturgy, with the holy Mother of God, the apostles, all the saints, and the multitude of those who have already entered the kingdom. 1187

Baptism
This sacrament is also called "the washing of regeneration and renewal by the Holy Spirit," for it signifies and actually brings about the birth of water and the Spirit without which no one "can enter the kingdom of God." [Titus 3:5; Jn 3:5] 1215

Where is the Liturgy Celebrated?
A church, "a house of prayer in which the Eucharist is celebrated and reserved, where the faithful assemble, and where is worshipped the presence of the Son of God our Savior, offered for us on the sacrificial altar for the help and consolation of the faithful - this house ought to be in good taste and a worthy place for prayer and sacred ceremonial." [Presbyterorum Ordinis 5; SC 122-127] In this "house of God" the truth and the harmony of the signs that make it up should show Christ to be present and active in this place. [SC 7] 1181

The gathering of the People of God begins with Baptism; a church must have a place for the celebration of Baptism (baptistry) and for fostering remembrance of the baptismal promises (holy water font).
The renewal of the baptismal life requires penance. A church, then, must lend itself to the expression of repentance and the reception of forgiveness, which requires an appropriate place to receive penitents.
A church must also be a space that invites us to the recollection and silent prayer that extend and internalize the great prayer of the Eucharist. 1185

It is in these churches that the Church celebrates public worship to the glory of the Holy Trinity, hears the word of God and sings his praise, lifts up her prayer, and offers the sacrifice of Christ sacramentally present in the midst of the assembly. These churches are also places of recollection and personal prayer. 1199