Before his arrest, Jesus ate the Passover meal with his disciples, but transformed its meaning as he did so, from a meal celebrating liberation from Egypt to one celebrating the liberation from sin and death which he was to achieve by his death on the cross. He himself was to be the sacrificed Passover lamb shared by God’s people.
Jesus took the bread, and identified it with himself: ‘This is my body which will be given for you’ (Luke 22:19). After they had eaten the lamb together, he took the cup of wine and identified that with himself as well: ‘This is my blood, the blood of the covenant, which is to be poured out for many’ (Matthew 26:28). Jesus was saying, ‘This is me, giving myself for you.’ Catholics believe that Jesus meant what he said, and that this is still true today when we do the same in memory of him. When we eat the bread, and drink from the chalice, it is the Lord himself we receive. This is because Jesus actually changes the deepest reality of the bread and wine (their ‘substance’), regardless of how they appear, into his own Body and Blood. By the power of the Spirit, they become the ‘Blessed Sacrament’ of the Lord’s body given for us, his blood shed for us.
There is much more to the Eucharist than reading the Scriptures, saying prayers and receiving the Lord’s presence in Holy Communion. It is Jesus’ body given for us and his blood shed for us that is present, in other words Jesus sacrificing himself for our salvation. By taking part in this celebration, we are made ‘at one’ with Jesus in his once-for-all sacrifice.
The Eucharist is the greatest act of worship we can give to the Father. We are not worshipping on our own, trying to reach God of our own accord, but in deep communion with Jesus in his worship, his total giving of himself.