The cup, in this instance, is that of a kingly cup, as explained in verses 41-44. Kings had cup bearers that would drink the wine before the king to prove that there was not any poison in it. Jesus takes the ask of positions of authority as James and John wanted to govern on each side of Jesus as King. Jesus instead says he is drinking the cup as a servant, taking the cup that is poisoned with suffering and death.
Blessed are the poor in spirit: for theirs is the kingdom of heaven. 4Blessed are they that mourn: for they shall be comforted. 5Blessed are the meek: for they shall inherit the earth. Blessed are they that hunger and thirst after righteousness: for they shall be filled. Blessed are the merciful: for they shall obtain mercy. Blessed are the pure in heart: for they shall see God. 9Blessed are the peacemakers: for they shall be called sons of God. Blessed are they that have been persecuted for righteousness’ sake: for theirs is the kingdom of heaven. Blessed are ye when men shall reproach you, and persecute you, and say all manner of evil against you falsely, for my sake. Rejoice, and be exceeding glad: for great is your reward in heaven: for so persecuted they the prophets that were before you.
I am not speaking of all of you; I know whom I have chosen. But the Scripture will be fulfilled, ‘He who ate my bread has lifted his heel against me.’ I am telling you this now, before it takes place, that when it does take place you may believe that I am he. Truly, truly, I say to you, whoever receives the one I send receives me, and whoever receives me receives the one who sent me.”
But you must remember, beloved, the predictions of the apostles of our Lord Jesus Christ. They said to you, “In the last time there will be scoffers, following their own ungodly passions.” It is these who cause divisions, worldly people, devoid of the Spirit. But you, beloved, building yourselves up in your most holy faith and praying in the Holy Spirit, keep yourselves in the love of God, waiting for the mercy of our Lord Jesus Christ that leads to eternal life
but now I am going to him who sent me. None of you asks me, ‘Where are you going?’ Rather, you are filled with grief because I have said these things. But very truly I tell you, it is for your good that I am going away. Unless I go away, the Advocate will not come to you; but if I go, I will send him to you. When he comes, he will prove the world to be in the wrong about sin and righteousness and judgment: about sin, because people do not believe in me; about righteousness, because I am going to the Father, where you can see me no longer; and about judgment, because the prince of this world now stands condemned.
“I am the true grapevine, and my Father is the gardener. He cuts off every branch of mine that doesn’t produce fruit, and he prunes the branches that do bear fruit so they will produce even more. You have already been pruned and purified by the message I have given you. Remain in me, and I will remain in you. For a branch cannot produce fruit if it is severed from the vine, and you cannot be fruitful unless you remain in me.
But we continue to preach because we have the same kind of faith the psalmist had when he said, “I believed in God, so I spoke.”
The spirit of the Lord GOD is upon me, because the LORD has anointed me; he has sent me to bring good news to the oppressed, to bind up the brokenhearted, to proclaim liberty to the captives, and release to the prisoners.. . . .
But you, O Bethlehem of Ephrathah, who are one of the little clans of Judah, from you shall come forth for me one who is to rule in Israel.
Mind your heart and hope.