I know the Eucharistic implications of this are significant, and I have heard that the cup on the cross is the fourth cup. But that being so, why did Jesus say, “I will never drink of the fruit of the vine until that day when I drink it new in the kingdom of God?”
From Scott Hahns Lambs Super
After all, he declared very clearly, “I will not taste of the fruit of the vine again until I drink it new with you in the kingdom” - - until my glory is established, until the purpose for my coming is realized. And if you follow Jesus’ footsteps from the Mount of Olives to the trial and to the sentencing and to the carrying of the cross up Calvary, you discover that he followed through on his resolution. For instance, there in Mark 15:23, we read, “On the way up to Golgatha, they offered him wine mingled with myrrh, but he did not take it.” He refused the wine. After all, what did he say? “I’m not going to taste the fruit of the vine again until my kingdom has come, my glory is revealed.”
Now, what exactly does that mean? When is it that Christ’s kingdom comes? When is it that his glory is revealed? I think most of us would assume that the answer is the second coming, the final advent when our Lord returns and establishes his eternal kingdom and manifests his divine glory for all the world to see and for the rest of eternity.
But that is not the perspective of the New Testament in the gospels, especially John. In the fourth gospel, the Gospel of John, we have a very penetrating insight into what Jesus meant when he spoke of his kingdom, when he referred to his glory, when he spoke about the real purpose for his coming. For instance, in John 12, we read, "Jesus answered them, ‘The hour has come for the Son of Man to be glorified. Now is the judgment of this world. Now shall the ruler of this world be cast out and I, when I am lifted up from the earth, will draw all men to myself.’ "
What was he talking about? He says, “Now is the hour of glory. The hour has come for the Son of Man to be glorified.” It sounds like the reference to the end of time, when the Son of Man comes riding on the clouds. “Now the judgment of this world begins. The ruler of this world will be cast out.” That sounds like the expulsion of Satan and the consignment of his legions to hell for eternity. “And I, when I am lifted up from this world from the earth, will draw all men to myself.” Perhaps that refers to Christ gathering the elect and taking them home to heaven.
But that is not Jesus’ meaning. John makes it clear, “When I am lifted up from the earth, I will draw all men to myself. He said this to show by what death he was to die.” John has a very profound spiritual insight here for us. We assume that Jesus’ kingdom and glory are primarily physical and visible realities, when, in fact, the glory of Christ’s kingdom is the truth and the love that he manifested upon the cross. So for Christ, in his own conscious thought, he understood that when he died that shameful ignominious death on the cross, there on Calvary, at that moment of shame and agony and horror – for the first time in history, the greatest manifestation of God’s love became available to all the earth.
see
zuserver2.star.ucl.ac.uk/~vgg/rc/aplgtc/hahn/m5/lmbsp.html
zuserver2.star.ucl.ac.uk/~vgg/rc/aplgtc/hahn/m4/4cp.html