CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 1086–1089

1086 "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."
1087 Thus the risen Christ, by giving the Holy Spirit to the apostles, entrusted to them his power of sanctifying: they became sacramental signs of Christ. By the power of the same Holy Spirit they entrusted this power to their successors. This "apostolic succession" structures the whole liturgical life of the Church and is itself sacramental, handed on by the sacrament of Holy Orders.
1088 "To accomplish so great a work" - the dispensation or communication of his work of salvation - "Christ is always present in his Church, especially in her liturgical celebrations. He is present in the Sacrifice of the Mass not only in the person of his minister, 'the same now offering, through the ministry of priests, who formerly offered himself on the cross,' but especially in the Eucharistic species. By his power he is present in the sacraments so that when anybody baptizes, it is really Christ himself who baptizes. He is present in his word since it is he himself who speaks when the holy Scriptures are read in the Church. Lastly, he is present when the Church prays and sings, for he has promised 'where two or three are gathered together in my name there am I in the midst of them."'
1089 "Christ, indeed, always associates the Church with himself in this great work in which God is perfectly glorified and men are sanctified. The Church is his beloved Bride who calls to her Lord and through him offers worship to the eternal Father."