Jesus said "I am the living bread that came down from heaven; if any one eats of this bread he will live for ever; he who eats my flesh and drinks my blood has eternal life and ... abides in me, and I in him (Jn 6:51, 54, 56)

The Eucharistic celebration always includes: the proclamation of the Word of God; thanksgiving to God the Father for all his benefits, above all the gift of his Son; the consecration of bread and wine; and participation in the liturgical banquet by receiving the Lord's body and blood. These elements constitute one single act of worship.

Because Christ himself is present in the sacrament of the alter, he is to be honored with the worship of adoration. "To visit the Blessed Sacrament is... a proof of gratitude, an expression of love, and a duty of adoration toward Christ our Lord"

"No one may take part in it unless he believes that what we teach is true has received baptism for the forgiveness of sins and new birth, and lives in keeping with what Christ taught."

The Catechism of the Catholic Church 1322-1419