The ESV Study Bible calls Matthew 18-20, “The Community of the Messiah Revealed.” In these chapters, Jesus describes the character of the New Covenant community. We learn how disciples are to relate to one another. For the next several weeks, I hope to take a small part at a time and point to the major idea. Today, I start with Matthew 18:1-6.
Matthew 18:1–6 (ESV)1 At that time the disciples came to Jesus, saying, “Who is the greatest in the kingdom of heaven?” 2 And calling to him a child, he put him in the midst of them 3 and said, “Truly, I say to you, unless you turn and become like children, you will never enter the kingdom of heaven. 4 Whoever humbles himself like this child is the greatest in the kingdom of heaven. 5 “Whoever receives one such child in my name receives me, 6 but whoever causes one of these little ones who believe in me to sin, it would be better for him to have a great millstone fastened around his neck and to be drowned in the depth of the sea.
The disciples are overly concerned about how one receives the title “The Greatest” in the kingdom of heaven. Jesus uses an unexpected object lesson to explain his answer. What did He teach by bringing a child to the center of the discussion?
A child is humble in that usually children have no concern about social status. Leave alone two children together of different rank and class, and usually, they will still play together. It is true some children immediately want to rule others, but most just want to have fun. In the sense that they don’t care about social rank, they are humble. Jesus is trying to get His disciples to not worry about rank in God’s kingdom.
Instead of worrying about status, disciples should focus on service. Even today, those who work with children and who receive them are often the unappreciated, unsung servant heroes in the church. Yet, children’s workers are the main idea of the text here. Children in verse five refers to disciples who have humbled themselves like children.
Jesus pictures a community of believers who relate to one another humbly. None is seeking to lord over another. None is trying to usurp the authority of another. All humbly work together. Disciples who humbly receive one another also receive Jesus, because Jesus identifies that closely with his disciples. However, the one who causes those seeking to humbly serve Jesus to sin is in for problems. Falling into the sea with a large weight tied to you would be a better than what the sin-causer will get.
Jesus calls us to a counter-cultural model of service, because He insist that we serve with humility. Humility does not fit in a “selfie” world. What advances one in today’s world is self-promotion. Humble servants move His kingdom forward and lead its advance. Prideful people build their own kingdoms and cause others to stumble. Those who follow Jesus should relate to one another and to others with humility.
 Carson, D. A. “Matthew”. In The Expositor’s Bible Commentary, Volume 8: Matthew, Mark, Luke, edited by Frank E. Gaebelein. Grand Rapids, MI: Zondervan Publishing House, 1984, 397.