In his gospel Mark tells of one of the instances which show the first disciples of Jesus subject to very human failings.  (Mark 9: 33-37)  The passage reveals the disciples were not free of human ambition, a kind of self-seeking, which led them to desire to be above others.  They argued among themselves about who would be the greatest in the kingdom.

And there is the case of James and John who approached Jesus with the request they be given the places of highest honor when Jesus comes to glory.  (Mark 10: 35-40)
When Jesus was confronted with those instances of self-seeking by his first disciples he had to correct their thinking.  When they asked about who is the greatest, Jesus responded by proposing a little child as an example. He told his disciples: “Unless you change and become as little children, you will not enter the kingdom of God.”
That response raises two questions.  What is the “kingdom of God”?  What does becoming like little children have to do with it?

The phrase “kingdom of God” does not appear in the Old Testament.  There are equivalent expressions which seem to reflect the ancient Israelites expectation that the Messiah would restore the kingdom of Israel in a political sense. That was never Jesus’ purpose nor his understanding of the kingdom.

From the many references to the kingdom of God in the New Testament it would be difficult to formulate a short, precise definition of what that kingdom is.  One thing is clear, however.  The kingdom has to do with Jesus coming and his mission.  The mission of Jesus was to bring grace and salvation to the humankind.

What, then, does becoming little children have to do with the kingdom in that sense? Obviously there are ways it is not desirable to become like little children.  To mention just two:  little children can be and often are selfish.  Little children can be cruel.  Of course, there is a certain ignorance that keeps them from understanding the wrongfulness of their behavior.

There is also another common trait of the behavior of little children. They know instinctively their dependence on others, primarily their parents.  They know they cannot provide for themselves the necessities of life: food, shelter, clothing, and help, even in a crisis as minor as a skinned knee.

What Jesus seems to be telling us is we need to recognize our complete dependence on his help, his grace.  This requires openness, humility, and gratitude. We are weak and selfish, but loved by God