The Catholic Church is fundamentally liturgical and sacramental in its public life of worship. As explained in greater detail in the Catechism of the Catholic Church, the liturgy is something that “the whole Christ”, Head and Body, celebrates — Christ, the one High Priest, together with his Body, the Church in heaven and on earth.
In the liturgy of the Church, God the Father is blessed and adored as the source of all the blessings of creation and salvation with which he has blessed us in his Son, in order to give us the Spirit of filial adoption.1110
Christ’s work in the liturgy is sacramental: because his mystery of salvation is made present there by the power of his Holy Spirit; because his Body, which is the Church, is like a sacrament (sign and instrument) in which the Holy Spirit dispenses the mystery of salvation; and because through her liturgical actions the pilgrim Church already participates, as by a foretaste, in the heavenly liturgy.1111
The mission of the Holy Spirit in the liturgy of the Church is to prepare the assembly to encounter Christ; to recall and manifest Christ to the faith of the assembly; to make the saving work of Christ present and active by his transforming power; and to make the gift of communion bear fruit in the Church.1112
From the Catechism of the Catholic Church, Paragraphs 1110-1112