It is a mistake to think that the Mass is a memorial service like that of Memorial Day, or a sort of imitation of the Last Supper, or a collection of prayers. he Mass is not just a collection of prayers, no matter how beautiful or moving they may be. Our Lord becomes present in the Mass, doing something deeply supernatural: performing a sacrifice. Before his passion, Jesus and his disciples were on the road to Jerusalem…He took the twelve aside and began to tell them what was going to happen to him…Jesus was going to offer his life to God as a ransom for our sins…
While Jesus was talking about giving oneself to God for others, by contrast the disciples argued among themselves about who was to wield power in the future kingdom.
An ardent desire filled Christ’s heart: a desire to go through his passion and death and to leave a perpetual memorial of his sacrifice. On the night of the Last Supper, Christ instituted the Mass. He offered his body and blood under the species of bread and wine to God the Father.