The word covenant means agreement. In the Old Testament (the first part of the Bible, written before Jesus’ life on earth) God made a covenant with the people of Israel. If they kept His laws, He would protect and bless them. But it wasn’t possible to perfectly keep God’s laws, and since the payment for sin is death (Romans 6:23), the Old Covenant included a way for an animal to take the place of the sinner. The animal (such as a lamb) died in the place of the person.
But the prophets also wrote about another covenant in the future. Now, Jesus was referencing that New Covenant (verse 20). As He celebrated Passover* with His disciples, He connected the bread and wine to his own death. The bread symbolised His body, and the wine was a symbol of His blood. Jesus was going to willingly die in the place of sinners, taking the punishment earned by their wrongdoing. He was going to become “the lamb of God, who takes away the sin of the world” (John 1:29).
That’s why Christians re-enact ‘The Lord’s Supper’ (also called Communion). We eat a piece of bread and drink a sip of wine or grape juice, to remember Jesus’ death for us (verse 19). There isn’t anything magical or life-changing about the bread and wine. But this is a very special time for Christians – a way of expressing our faith in Jesus, and our desire to live closely to Him. Just as food and drink supports physical life, Christians depend on Jesus for spiritual life.
The New Covenant is God's agreement with humanity to forgive anyone who trusts in Jesus. It is only by Christ's sacrifice for us that the record of our sin can be wiped clean. But our part is to repent (confess our sin and leave it behind) and believe. It is only by committing ourselves to Jesus that we can receive forgiveness and God's Fatherly welcome.
“Do this in remembrance of me”
Luke 22:19