Jesus makes it clear that being the greatest is really not that important in the Kingdom of God. Greatness brings with it authority, honour and power which are a breeding ground for sin. He’ll get to that in a moment. In a physical kingdom authority, honour and power are important to the structure of the society and the maintenance of rule but the Kingdom of God is different. He reminds them that little children have what it takes to enter the Kingdom. They don’t have authority, honour and power but their humbleness, simplicity and gentleness all make it easy for them to follow Jesus. Most children will quickly acknowledge the wrong they’ve done and have an attitude of repentance, unlike adults who seek to excuse their actions. So children have what it takes to enter the Kingdom even if from a human point of view they don’t offer much in the way of benefit to the Kingdom. Jesus challenges his disciples to willingly welcome children as a sign that they’re not looking at what they bring into the Kingdom but only what the Kingdom offers them. Likewise all people should not be seen for their status and what the bring with them. It is what the Kingdom offers them that is important.
At this point the disciples must have felt terribly ashamed of their petty argument about who was the greatest if children had what it takes. They keep on getting caught thinking that this kingdom that they were anticipating was some sort of physical entity. A place where there would be a hierarchy and benefits to being higher up the ladder so they all wanted to be as close to the top as possible. John even mentions that there were others operating in the area that were using the name of Jesus to do good. There was competition from outside their select group! But Jesus will have none of it. Jesus says that people can’t confess allegiance to him one moment and then the next moment stand against him, so they’re either for him or against him.
Then he jumps to the issue of sin and how it should be handled by the citizen of the Kingdom of God. This was after all the real issue that needed dealing with in this discussion on who was the greatest among them. Sin must not be tolerated because it infects the whole body. He instructs them to be radical about how it is dealt with. No where later in scripture do we read Paul, Peter, John or James saying to cut the foot or hand off or pluck out the eye if it causes sin. They all knew what Jesus said here so they had understood his use of imagery. The disciple of Jesus needs to separate himself from sin and was not to tolerate it’s presence nor it’s infectious growth. Sin touches the inner man, his soul and this doesn’t die it will live on even in hell and that’s where sin leads those it consumes.
Jesus closes this talk off with a comment about fire and salt, both of which are symbolic in scripture. Fire purifies, it is the presence of God found in the pillar of fire that went with the Israelites in the dessert, it’s what came from heaven and consumed the offering and alter of Elijah and it will in a short time appear at Pentecost as a sign of the filling of the Holy Spirit. Salt was added to the grain offerings as a purifying agent, it seasoned their food, served as trading currency but lost all its value if it lost its saltiness. Jesus uses this to remind his disciples to stay pure and to allow themselves to be purified, it was a necessity to enter the Kingdom. He says “have salt in yourselves, and be at peace with each other.” He pointed them right back to their argument on the road to Capernaum where they were at odds with each other because of the impurities in their hearts that still needed cleansing.
Jesus did let the sinful attitudes of his disciples go unchecked. He forced them to face the reality of their hearts and their need to change. He still does the same today.