Catechism of the Catholic Church
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."' 11
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." 12
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.