CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 1102–1106

1102 "By the saving word of God, faith . . . is nourished in the hearts of believers. By this faith then the congregation of the faithful begins and grows." The proclamation does not stop with a teaching; it elicits the response of faith as consent and commitment, directed at the covenant between God and his people. Once again it is the Holy Spirit who gives the grace of faith, strengthens it and makes it grow in the community. The liturgical assembly is first of all a communion in faith.
1103 Anamnesis. The liturgical celebration always refers to God's saving interventions in history. "The economy of Revelation is realized by deeds and words which are intrinsically bound up with each other. . . . [T]he words for their part proclaim the works and bring to light the mystery they contain." In the Liturgy of the Word the Holy Spirit "recalls" to the assembly all that Christ has done for us. In keeping with the nature of liturgical actions and the ritual traditions of the churches, the celebration "makes a remembrance" of the marvelous works of God in an anamnesis which may be more or less developed. The Holy Spirit who thus awakens the memory of the Church then inspires thanksgiving and praise (doxology).
1104 Christian liturgy not only recalls the events that saved us but actualizes them, makes them present. The Paschal mystery of Christ is celebrated, not repeated. It is the celebrations that are repeated, and in each celebration there is an outpouring of the Holy Spirit that makes the unique mystery present.
1105 The Epiclesis ("invocation upon") is the intercession in which the priest begs the Father to send the Holy Spirit, the Sanctifier, so that the offerings may become the body and blood of Christ and that the faithful by receiving them, may themselves become a living offering to God.
1106 Together with the anamnesis, the epiclesis is at the heart of each sacramental celebration, most especially of the Eucharist:

You ask how the bread becomes the Body of Christ, and the wine . . . the Blood of Christ I shall tell you: the Holy Spirit comes upon them and accomplishes what surpasses every word and thought. . . . Let it be enough for you to understand that it is by the Holy Spirit, just as it was of the Holy Virgin and by the Holy Spirit that the Lord, through and in himself, took flesh.