The trip that is described in Matthew 20:17–19 has a definite purpose.
Recognize the purpose in Jesus’ trip to Jerusalem. Jesus went to Jerusalem to be crucified for you. Jesus had given earlier indications of his impending suffering and death, Matthew 16:21; 17:12, 22-23. The beginning of the journey is indicated in Matthew 19:1, and with Matthew 21 he enters the city. The time was the celebration of the Passover feast. Jesus and his disciples were among the crowds making the trip, when Jesus took the twelve aside on the way to prepare them for what was to happen. Jesus presents himself as the true Passover lamb, the fulfillment of all the acts of redemption God had accomplished in the Old Testament. Happen. This prophecy is more specific than earlier ones. It implies a trial by the Sanhedrin (since he is to be condemned), and specifies that it is at the hands of the Gentiles that he will be actually mocked and executed. Even crucifixion is specified.
Believe that the Son of Man had to suffer in your place. Jesus is consciously carrying out the will of his Father in heaven. The certainty of what will happen (reflected in the future tenses) reflects the fact that his work is directed first of all to his Father. It is God’s righteous wrath against sin which he is satisfying by his death. (Remember that the Son was sent by the Father precisely for this purpose. The persons of the Trinity work together to accomplish your salvation.) Matthew has described increasing opposition from the leaders of Israel. He also shows your Savior’s growing determination to carry out the work assigned to him. Matthew 1:21 showed the purpose of the Incarnation. Now the Savior is carrying out what he had come to do. Jesus uses the self-designation, “Son of Man,” with its reflections of glory from Daniel 7, to refer to his impending death. The contrast highlights the suffering which he will undergo in your place. “It is not that He must undergo humiliation, suffering and death because He is the Son of man, but that although He is the Son of man such a destiny is, paradoxically, in store for Him.” (Geerhardus Vos, The Self-Disclosure of Jesus, p. 236)
Trust the Savior who was killed and raised for you. Trust in Christ’s death. Very likely one of the purposes of Jesus taking the disciples aside and informing them (again) of what was to happen was so that their trust in him would not be shaken. They had their own notions of the work of the Messiah and the kind of kingdom he would establish, as Zebedee’s wife’s request shows, verses 20, 21. Jesus specifies that his death will be a ransom, v.28. It is the payment of a price. Just as one might pay a specific price for the redemption (from slavery) of a specific individual, so Christ gives his life as a ransom for many. The Lord’s Supper, which he would soon institute in the presence of his disciples, focuses on that death. It portrays for you, using signs which your senses can appreciate, the Lord in his death and resurrection. Thus it becomes one of the means of grace God uses to strengthen your faith in Christ. Your self-examination involves asking yourself if you really trust in and depend on Christ as your Savior.
Rejoice in the resurrection of your Savior. The path Jesus is walking leads to Jerusalem. It leads into the city, and back outside the walls to Golgotha, Matthew 27:33. But that is not the end of the journey. From Golgotha the path leads to the garden where Joseph of Arimathea has had a new tomb carved out of the rock. And the path will lead from that tomb to glory! Again Jesus turns the expectations of the world upside down. His death is not the end of the story. His resurrection is crucial to his saving work. A savior who was still in the tomb would save no one. But this Savior would be raised on the third day. “His messianic consciousness, which he immediately expressed in the name ‘Son of Man,’ implied the certainty that he had to die. But the moment he made this openly and plainly known to his disciples, he also announced that he would rise again in three days and subsequently be taken up into the glory of his Father, where he would sit at his right hand and be once more manifested for the purpose of judgment (Matt. 16:21, 27; 20:18–19; 25:31; 26:64).” (Herman Bavinck, Reformed Dogmatics, Vol. 3, p. 423) The passive indicates that in the resurrection, as well as in his death, Jesus is primarily being acted upon. He is your representative. What happens to him, happens also to you. Thus the very institution of the Lord’s Supper contains Jesus anticipation of drinking of the fruit of the vine anew in the Father’s kingdom, Matthew 26:29. Paul can remind you to “proclaim the Lord’s death until he comes,” 1 Corinthians 11:26.
The purpose of the journey Jesus is on may seem grim, and indeed it is. But Jesus tells you, not only of his death, but also of his resurrection in your place. And he tells you of his journey, so that ultimately you can share his destination, not the Jerusalem in Palestine, but the New Jerusalem, the heavenly city, where righteousness dwells.