"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 under the Eucharistic species. He is present in the sacraments, so that when a man 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. He is present, lastly, when the Church prays and sings. Christ indeed always associates the Church with Himself in this great work wherein 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."
(Constitution on the Sacred Liturgy  Sacrosanctum Concilium n. 7)