What does Mark 9:34 mean?

The disciples are displaying the same prideful assumptions as the Pharisees in Luke 14:7–11. Jesus tells the Pharisees a story about a guest at a wedding feast who faces a choice to take an honorable seat commensurate to his position or to sit in a lowlier spot. He finds that if he takes the higher seat, the host of the wedding will tell him to move down when an even higher-ranked guest arrives. But if he takes a seat at the lower end of the table, the host will see him and, in front of all the guests, tell him to move up. Jesus finishes the story by saying, "For everyone who exalts himself will be humbled, and he who humbles himself will be exalted" (Luke 14:11).

Peter, James, and John had been selected to see Jesus' transfiguration, but they are fishermen. Others, like Matthew, had more profitable jobs. Later, James and John's mother will ask Jesus to give her sons positions of prominence in His kingdom (Matthew 20:20–28). The disciples have all but forgotten Jesus' warning that His followers must be willing to give up their lives because this world means nothing compared to what He offers (Mark 8:34–38).

To be great in God's kingdom is to realize that we are not great. We are not worthy of forgiveness or consideration or position. God's notice of us and blessings for us are because of His love, not our effort (Ephesians 2:8–9). And so the "greatest" in Jesus' kingdom is the person who acknowledges this by seeking God, rather than seeking themselves..