Our culture has a problem, and since the Church today is very driven by this culture, the Church has a problem too. We love liberty and democracy so much that we have carried it into every are of our lives. We want every inequality to be ironed out. We want everyone to be equally good at everything. We want men and women to be the same. We want all our kids to be winners. We want everyone to go to college and get the same grades and the same job. Any time anyone rises above the norm we shoot them down with media hit pieces or seek some way to hold them back. When people fall behind we make excuses and give them passing grades anyway. Welcome to egalitarian America.
Unfortunately this is not the world God created. There are very real difference between all of us, that is the blessing of variety. And there is a sense in which we are all the same, before God each a valuable living soul. That is the character of a trinitarian God and the world he created after that character. He is both one and three, both unity and diversity.
So when we encounter the disciples arguing about who was the greatest in the kingdom (Mark 9:33-37) we might easily overlook the fact that he told them how to do it. As if arguing were not bad enough, they had the audacity to argue about someone being better than someone else, we might think. But in reality arguing is not an evil, even contentious arguing. Chesterton said that “people quarrel because they cannon argue”. Forming arguments and defending and attacking position is iron sharpening iron. That is what makes us stronger, so that we might defeat the difficult enemies that will come. Similarly in Luke 14:7-11 Jesus told his hearers how to get the place of honor at the next wedding feast. In this case the standard for earth and heaven touched, they were one and the same. The same standard that gets you at the head of the table in heaven will also get you to the head of the table at your local wedding hall. But that is not always the case.

Christ with the Children, Carl Bloch
It is fairly clear that they had no idea what he was talking about when he silenced their arguing by telling them the standard for the kingdom of heaven. In this case the rules are different for the kingdom of heaven and that of earth. They were still thinking about an earthly kingdom even when Jesus was crucified. Luke 22 seems to indicate that another similar argument broke out in the upper room shortly before the crucifixion. Apparently a discussion of who would betray Jesus turned into a question of who was the greatest. Yet shortly thereafter he told them he was to die and they still couldn’t understand. This was the messiah, he was to usher in a kingdom and vanquish all of his enemies like the mighty king that he was. They were arguing who was the greatest by the earthly standard, for earthly kingdoms. He didn’t criticize their zeal or ambition, but he pulled back the curtain and showed them the way greatness is measured in the kingdom of Heaven. The real behind the scenes kingdom, the kingdom that will last forever. In this kingdom you must have the humility of a child and die to yourself. This was one of the many instance where Jesus said things that came to have meaning after the resurrection.
In a sense Judas was the first to understand that Jesus was training them for a heavenly battle that was not always fought by the rules of this earth. He rejected it, but the other disciples soon got on board. They realized that Jesus had called them to another battle. Not that warfare with swords was inherently bad, but that was not what they were about. In the kingdom of heaven if you want to be first, you must sacrifice yourself. The path to greatness is the path of Jesus, the path of dying to self, giving all that you have for others. To want the benefits of greatness without the hard work of killing your desires and replacing them with humble service is to only measure by this world.

Third century church ceiling, Ihlara Valley, Turkey. Depicting Jesus surrounded by his 12 apostles. 38.252997º N, 34.309368º E
Sometimes a man can become great in both kingdoms at the same time. We must be wise in discerning what the scripture teaches and how it applies to our situation. We can’t automatically conclude that because a man is successful on this earth that he is nothing in the kingdom of heaven and vise versa.
But we all will be equal after death right? Everyone in heaven will be equally in joy and everyone in hell in pain, right? Not really. Jesus’ words in Luke 10:12 seem to indicate that there are levels of judgement. Matthew 10:42 seems to indicate that there are levels of reward. I Corinthians 3:10-15 warns about the quality of our work here on earth. If we mess around and waste our gifts, sure we might make it to heaven, but just barely and with no reward.
So there is a real measuring rod. Some will be rewarded higher than others. Jesus pulled the veil back and showed us by what standard we are to measure. These 12 men would rule the 12 tribes of Israel on 12 thrones Matthew 19:28. These men would all be the greatest because they gave of themselves and died. There are real works we can do. We can strive to be the best in the kingdom of heaven. But, this, only by the grace of God and only by dying.

Royal Portal, Chartres Cathedral. c. 1215 Depicting Jesus surrounded by the four evangelists, below the 12 apostles, surrounded by many saints who are also greater in the kingdom than we.