What a Teacher We're So Lucky to Have!
It is quite upsetting, on the human level, to hear that the disciples who seem to have the hardest time to understand the teaching of Jesus and to accept God's way are those who are closest to Jesus. After all, Peter, James and John are the privileged disciples. Besides witnessing with other disciples Jesus's power at different healings and his teaching authority, they are the only three who Jesus would select to be at special events in his life and ministry, such as the cure of Peter's mother-in-law (1:29-31), the raising of Jairus's daughter (5:35-43), and the transfiguration (9:2-8). Moreover, the three of them, together with Andrew, have been with Jesus the longest, since they were the first of the disciples whom Jesus called (1:16-20). And yet, they are the ones who fail to understand Jesus over and over again. As a result, though Jesus has just told them - for the third time - that he would be condemned to death, James and John still tell Jesus, "We want you to do for us whatever we ask of you." The other ten are not much better, since "they become indignant at James and John" when they hear of their request.
Yet, Jesus would not fail them. Patiently, over and over again, he teaches them, explains God's way to them, and forewarns them of what will happen to them. Most consolingly, Jesus does not give up on them. By the fact that he keeps inviting them to live his way, he shows his trust in them. In addition, he prepares them to become true leaders in the community of his followers.  Ultimately, he inspires them to live as he does. "Whoever wishes to be great among you will be your servant; whoever wishes to be first among you will be the slave of all. For the Son of Man comes to serve, and to give his life as a ransom for many."
 Francis J. Moloney. The Gospel of Mark: A Commentary. Peabody, MA: Hendrickson, 2002; p. 206-7.