Who is the most important in the Kingdom of Heaven?

All of us have self-esteem issues at one time or another—either too little or too much.  Today Jesus teaches us to be like little children, the lesser ones in society.  They are the greatest in the Kingdom.  We are to be as humble as they.  This is something quite radical since the value ascribed to children in Jesus’ time was rather different than it is today, yet Jesus warns us that they receive special care by their angels who look upon the Father’s face.  Where are we failing to be as a child? Do we act in belief and trust that it is God who protects us, provides for us, and on whom we can put all our burdens and fears?