Holy Communion, the Eucharist, the Lord's Supper, the Sacrament of the Altar, the Lord's Table; these are all names given to the meal which Jesus Himself instituted on the night He was betrayed, what is commonly called Maundy Thursday.
Lutherans stand virtually alone in their understanding of the Lord's Supper. The understanding needs to be broken down into two important questions:
1. What is it?
2. What does it do?
What is the Lord's Supper? It is the true body and blood of Jesus. Jesus Himself says this in 3 of the 4 Gospels. The words are also recorded by Saint Paul: "This is my body...This cup is the new covenant in my blood" (I Corinthians 11:24-25). Lutherans do not argue with Jesus on this point. He said it. That makes it so.
To be sure, this is a mystery. We do not try to explain how the body and blood of Jesus is present. It is a matter we simply take on faith. Again, Jesus said so. We should trust His Word.
What does the Lord's Supper do? It unites me in communion with Jesus Christ (I Corinthians 10:16). Thus, through union with Christ my sins are given to Him, His righteousness is given to me, and I am drawn into fellowship with His holy Church through His body.
The Sacrament of the Altar is a complete gift. There is not a thing that pastor or parishioner can do to make it more holy. The pastor merely speaks the words of Jesus. Christ does all the work bringing His salvation, His once-for-all-sacrifice, into the mouths of His people.
When we receive the Lord's Supper we receive the body and blood of Jesus Christ. We receive unity with Jesus and with His body, His Church, across all time and space.
[Tomorrow: We stand for Absolution!]