Gethsemane provides the final lesson in discipleship given by Jesus before his execution and exaltation, and that lesson is rooted in prayer.
After establishing his communion with his disciples at the last supper Jesus for once takes them with him as he withdraws to pray, further emphasising the importance of this by picking out Peter and the sons of Zebedee, those who had witnessed his transfiguration on the mountain. Jesus prays alone, as on previous nights, but asks that they remain close and support him in his distress. His prayer allows us some sense of the struggle in the soul of Jesus, and suggests why he wishes the support of those who had been closest to him in his ministry.
We cannot fully penetrate the mystery of the agony of God's unique Son; we might see this in simplistic terms as a clash of wills: the human will of Jesus understandably recoiling from the appalling destructiveness of what is happening, pleading that if at all possible the cup of this suffering might pass from him without his having to drink of it, so that he might even at this late moment bypass the agony of the cross. Yet here as elsewhere Jesus submits himself, however reluctantly, to the will of his Father; with the will of the Son abandoning itself completely, reflecting completely the will of the Father.
Maximus the Confessor saw in Jesus's struggle the final and most stark test of his obedience. In his view, our wills were created to be in harmony with the divine will. When we sin, our wills are disordered, no longer being in harmony with God's will. The ultimate test of Jesus's obedience then, is depicted here in his prayer: praying first that if it is possible, that this cup pass; and then, nevertheless, that the Father's will be done. St Matthew shows how this prayer of Jesus is patterned on the one Jesus has taught to his disciples earlier, the Lord's prayer, perhaps so affirming that Jesus's relationship to the Father remained consistent throughout his life unto death.
The disciples, like ourselves, do not display such consistency of purpose. Told to watch with Jesus, perhaps even eager to do so, they fail. We are given no answer to the problem of the weakness of the disciples' and of our own flesh, other than that it is to be admitted and not to be underestimated. Jesus repeatedly finding his disciples failing him emphasises to him that the cup will not pass: he will go through his trial without the help of his disciples, who will, indeed, abandon him. Yet the prayer of Jesus is not without effect: it begins with him sorrowful and prostrate, and ends with him resolutely facing the approaching crisis. The Father is silent - what word has the Father except the Son? - yet Jesus's human will is now set unflinchingly towards the fulfilment of his Father's will, even to death on a cross.
The Son's sacrifice begins here, in the offering and transition of his human will into obedient harmony with the Father's will irrespective of what that might cost. Here in Jesus we see our wounded nature healed, restored to its real self; and also glimpse something of the challenge and cost our discipleship imposes on us.
Jesus knows their, and our, weakness; knows that the disciples are not yet ready to enter the trial with him, to drink the cup, to share his hour. But Jesus does not give up on them, does not give up on us. His final, dynamic command, 'Arise, let us go' - the last words Jesus will speak to his disciples in Matthew's account before the resurrection - indicates Jesus still wants their company, even if they - and we - stumble and fall away.
Arise, let us go: Jesus has uttered this command before, at the beginning of the preaching of the kingdom. Even though the disciples will scatter in failure and fear, Jesus has told them that after he has been raised he will go before them, as a shepherd leading his flock, into Galilee. Arise, let us go: no matter what our failures have been, no matter what the trials we fear to face, the crosses we fear to bear, we can trust that the Lord is with us, and leads us on where he has gone, into Galilee of the nations, into life with God.