" When Jesus celebrated His final Passover with His disciples, He departed from the standard liturgy in the middle of the celebration. He added a new meaning to the Passover celebration as He took the unleavened bread, attaching a new significance to it when He said, “This is My body which is broken for you.” Then, after the supper had been completed, He took the wine and he said, in effect, “I’m attaching a new significance to this element as you celebrate the Passover because this wine is my blood. Not the blood of the lamb in the Old Testament whose blood was marked on the doorpost, but now this cup is my blood.” In essence, Jesus was saying, “I am the Passover; I am the Paschal Lamb; I am the one who will be sacrificed for you. It is by My blood being marked over the door of your life that you will escape the wrath of God.” So He said: “From now on, this is My blood, which is shed for you for the remission of your sins. This is the blood of a new covenant.” This new covenant that He instituted that very night fulfills the old covenant, giving it its fullest and most meaningful expression. "
― R.C. Sproul , What Is The Lord's Supper? (Crucial Questions #16)