How inappropriate and how out of place for James and John to ask this of Jesus! Our first reaction is one of shock and dismay. Jesus' reaction appears to have been the same. "You don't know what you're asking," he says to them. "Are you able to drink the cup I will drink?" And along with the hymn, the two brothers declare boldly, "Lord, we are able." No doubt they believe that at the moment.
James and John seem to have ignored everything that Jesus had just said about his own suffering and death, and have jumped forward in time to focus on his coming glory. Then, they imagine they will be rewarded for having stuck by Jesus through troubled times. They talk to Jesus like politicians expecting rewards of patronage. They want cabinet positions in the new administration; "Grant us to sit, one at your right hand, and one at your left, in glory." Here is Jesus approaching his most troubled hour and James and John are competing for the positions of Secretary of State and Secretary of the Treasury!
The brothers did not truly understand what it meant to drink Jesus' cup. It was a metaphorical way of speaking of his own suffering, crucifixion, and death. That is why it seems so strange that James and John could make such a request. Had they not been listening as Jesus spoke to them along the way and over the months? The disciples are not listening.
The main problem with James and John's request was that they wanted the rewards without the suffering. They wanted Easter without Good Friday. The wanted the crown without the cross. They wanted the gain without the pain. They did not realize that the two places at Jesus' right and left hands would soon be occupied by persons hanging on crosses! And so Jesus had to teach them. He said, "You know that those who are supposed to rule over the Gentiles lord it over them, and their great leaders exercise authority over them. But it shall not be so among you" (10:43).
Yet down through the ages it has been so. The church has often absorbed the world's standards, almost by osmosis. We find it hard to accept Jesus' complete reversal of values. Basically what Jesus says is that the greatness of our lives will be measured by the amount of real service we render to others, not by the rank and privilege we receive.