On the first Sunday of the month, our church held the Lord's Supper (sometimes called Communion). While receiving, I thought of the texts describing its institution in the Synoptic Gospels and Paul's First Letter to the Corinthians; the last being the text read by the pastor.
These four are very similar, moving from the blessing and breaking of the bread by Jesus Christ, it's being described as his body broken for us, the blessing of the cup, it's being decribed as the New Covenant in Christ's blood shed for us for the remission of sins, with the sharing of the bread and wine among the disciples. The wording in Greek is not identical across the four sources, but this is probably due to the Messiah having originally spoken in Aramaic, and the New Testament sources reflecting translators' choices (having done Chinese-English tech and legal translation, I know that there are usually several ways to say the same thing).
But several thoughts crossed my mind while the ordinance was being observed.
(1) This is just the sort of remembrance to which some small, persecuted community rooted in Judaism would cling to most carefully.
(2) Yes, the parallels to the Passover seder are there, and doubtlessly deliberate. The symbolism also points to the sacrificial ritual of the times when the Temple still stood, and its connections to the blood of the Passover lamb sprinkled on the ancient Israelite doorposts also links it very closely to Old Testament religion.
(3) The language of sacrifice and atonement is unmistakable--blood poured out for the remission of sins. Yet how can Jesus, whom none can convict of sin, make atonement? The atonement is for the sins of others! This makes the key memory of the primitive church one of sacrifice and atonement. How then can the theologians of the 19th and 20th centuries dispense with the old Christian doctrine of penal substitution? How can the Muslims, since the 7th century, deny that Jesus died on the cross?