"For whenever you eat this bread and drink this cup, you proclaim the Lord's death until he comes." (1 Corinthians 11:26)
Paul addresses two issues in the Corinthian assembly: head coverings in worship and the abuse of the Lord's Supper. The head covering passage is deeply rooted in the cultural context of first-century Corinth and has been interpreted variously throughout the Church's history. The Catechism does not treat it as a permanent liturgical regulation but as an expression of the principle of order and propriety in worship that is permanent even if specific cultural expressions vary. The underlying principle, that worship should reflect the glory of God and be conducted with reverence and dignity, is not culturally relative.
The second half of the chapter contains the oldest written account of the institution of the Eucharist in the New Testament, predating even the Gospels. Paul writes that he received it from the Lord: on the night he was betrayed, the Lord Jesus took bread, gave thanks, broke it, and said: this is my body which is for you; do this in remembrance of me. In the same way, after supper, he took the cup saying: this cup is the new covenant in my blood; do this, whenever you drink it, in remembrance of me. For whenever you eat this bread and drink this cup, you proclaim the Lord's death until he comes. The Catechism calls this the central text of Eucharistic theology: the Eucharist is the memorial, anamnesis, of the Lord's death, not a mere recollection but a sacramental making-present of the one sacrifice (CCC 1362).
Paul then issues a severe warning about unworthy reception: whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord. A person ought to examine themselves before they eat and drink. For those who eat and drink without discerning the body of the Lord eat and drink judgment on themselves. This is why some among them are weak and sick, and some have fallen asleep. The Catechism grounds the obligation of preparation for Communion and the practice of abstaining when in a state of serious sin in this passage (CCC 1385).
Brothers and sisters, examine yourselves before you eat and drink. This is not a counsel for the scrupulous but a command for the whole community. Come to Communion with an examined conscience, having sought forgiveness for serious sin. The Eucharist is the proclamation of the Lord's death until he comes. Come worthy of what you proclaim.
Lord Jesus, on the night you were betrayed you gave us your body and blood and told us to do this in memory of you. Make us worthy to receive you. Let us never eat and drink without discerning your body. And let every Eucharist be a proclamation of your death until you come. Through Christ our Lord. Amen.