The Holy Eucharist completes Christian initiation. Those who have been raised to the dignity of the royal priesthood by Baptism and configured more deeply to Christ by Confirmation participate with the whole community in the Lord’s own sacrifice by means of the Eucharist. (Catechism of the Catholic Church, Article 3, 1212 1322)
The Eucharist is the source and summit of the Christian life and was instituted by Christ Himself in order to perpetuate the sacrifice of the cross throughout the ages until He should come again. It is entrusted to His beloved Spouse, the Church as memorial of His death and resurrection, as a sacrament of love, a sign of unity and of our sharing with Him to form a single body. (1331) In the Eucharistic sacrifice, the whole of creation loved by God is presented to the Father through the death and resurrection of Christ. Therefore, through Christ, the Church expresses gratitude to God for all he has accomplished through creation, redemption and sanctification. It is the sacrifice of praise by which the Church sings the glory of God in the name of all creation and made possible only through Christ: He unites the faithful to His person, to His praise, and to His intercession.
As a memorial of Christ’s passover, the Eucharist is also a sacrifice, manifested by the very words of institution: “This is my body which is given up for you."