Matthew shows us an odd exchange between Jesus and his disciples.
In Matthew 20:20–28, the mother of James and John, in typical motherly fashion, asks Jesus whether her nice, upstanding sons can sit beside Jesus in his kingdom. James and John, through their mother, are seeking prominence. They want to be great.
Jesus answers, in atypical fashion, with a question: “Are you able to drink the cup that I am to drink?” (Matthew 20:22). This is not a rebuke as we might expect. It’s a simple question to which the brothers reply, “Yes, we are able to drink the cup.”
They don’t understand what Jesus is saying. He then turns to his other disciples, who are angered by James’s and John’s request because they themselves desired the same prime placement at Jesus’s right hand. But Jesus sets them straight, and us. Greatness in the kingdom of God is obtained along the path of love — the path of sacrifice, service, suffering.
This is God’s economy, after all. Having more isn’t winning. Being served isn’t best. Being honored isn’t greatness. The people of Jesus are to follow in the footsteps of Jesus — who “came not to be served but to serve, and to give his life as a ransom for many” (Matthew 20:28).
Read more at http://www.desiringgod.org/blog/posts/the-cup-consumed-for-us