Luke 22:14-20 “And when the hour was come, he sat down, and the twelve apostles with him. And he said unto them, With desire I have desired to eat this passover with you before I suffer: For I say unto you, I will not any more eat thereof, until it be fulfilled in the kingdom of God. And he took the cup, and gave thanks, and said, Take this, and divide it among yourselves: For I say unto you, I will not drink of the fruit of the vine, until the kingdom of God shall come. And he took bread, and gave thanks, and brake it, and gave unto them, saying, This is my body which is given for you: this do in remembrance of me. Likewise also the cup after supper, saying, This cup is the new testament in my blood, which is shed for you.”
The supper Jesus ate with his disciples was not the Passover meal, but simply one of the meals during the Passover week. We know this because none of the details of this meal match what the Old Testament tells us about the Passover meal. This meal took place on the preparation day when the Passover lambs were killed. Jesus, as a matter of fact, was killed at precisely the time when the Passover lambs were being killed. The Passover meal was supposed to be eaten at midnight following the killing of the lamb. Some commentators think that Jesus and His disciples ate the Passover meal one day early. This is preposterous. The disciples did not have their shoes on their feet as commanded in the Old Testament concerning the Passover meal. They were not standing up with their staff in hand, as we would expect for the Passover meal. There is no mention of a lamb being eaten, and no mention of bitter herbs.
The disciples believed that the Passover meal was yet to take place on the following day, for we read in John 13:29 that when Judas got up and left the room, the other disciples thought that he went to buy things for the feast.
It is somewhat confusing in the Scriptures because the entire week is called the Passover, and preparations were being made for the Passover meal. However, it is certain that the meal Jesus ate with His disciples was not the Passover meal.
What we have here is a new and special meal for a new and special dispensation. Jesus instituted His Supper, a Supper we as Christians are to observe in our churches. It is a time to remember what the Lord has done for us when His body was broken and His blood was shed. It is a memorial service and not a way to be saved. We are saved by faith in Jesus, not by eating and drinking in the communion service.