Up to now in Matthew’s narrative, Peter often took the lead in things because he was the eldest of the Twelve, and apparently the largest physically. But Jesus had not yet designated who would hold what position in His future royal court. They had no doubt discussed this privately among themselves, but Jesus obviously knew about it. So far, only Peter was given any kind of title (keyholder) and that was typically not a full-time job. And perhaps they were somewhat worried about all this persistent warning from Jesus that He would be abused and executed. So they came and asked who was going to be His viceroy. Who should take charge in the absence of Jesus?
By this time they had been living communally together most of the time around Capernaum where Peter, Andrew, James, John and Matthew had all been living when Jesus called them into discipleship. These we also likely cousins of Jesus in the first place, and some of these men had wives or other family members living there, so it was a big homey atmosphere. Given what we know of housing in that part of the world, it was quite likely Jesus and His disciples hung out in the open courtyard virtually every home would have had. And the place would still be busy and packed with people. Thus, we are hardly surprised children of all ages would be wandering among the adults. Jesus grabbed one of the younger lads and sat him down in the middle of the group.
Who can say what the boy would have been thinking? In typical ancient Hebrew society, adult men seldom spent all that much time with even their own younger children. It was a sort of rite of passage when boys got old enough to start spending time with their fathers at whatever work they did, typically not before age six. This is when social gender roles were differentiated. Since the work of Jesus included a lot of talking and teaching about all those important adult things, the lad probably wondered if this was one of those moments hanging out with the adult menfolk.
Either way, he would have known to sit silently and try to absorb what was going on. In his world, adult men were nearly demigods, and all the more so this guest of honor in their community. Hebrew society suffered none of our modern smart-alecky children; this boy would have been respectful and downright subservient. Everything he hoped and dreamed about required trusting these men for guidance. He had no idea what to expect.
This is the primary point Jesus was making here. Greatness in the Kingdom of Heaven was rooted in this kind of unreserved trust. That means no preconceived notions about what to expect, but something of a blank slate, wide open to whatever God wants to write. All the more so when Jesus had already been making a point of shattering His disciples’ expectations regarding this business of being Messiah. The disciple who could be most childlike in absorbing like a sponge everything Jesus said is the one who would take the lead.
Further, the one who could set aside all his human expectations would be the most like Jesus. That’s the meaning of the protocol statement: “Whoever receives such a childlike believer in My name receives me.” It requires that level of trust and openness to exercise the authority of Heaven.
It’s altogether natural for fathers to guard their children’s minds from false teaching but it was also a solemn command of God (Deuteronomy 6:7). Even the Talmud bore echoes of this great duty. Jesus approaches it from the opposite angle and gives it a new emphasis. Given the total necessity for this level of unquestioning trust in the Kingdom of Heaven, those who do take leadership roles dare not abuse their position of trust. Great is the temptation to mislead someone for the mere sake of amusement. It’s no joke. Abusing someone’s trust is teaching them to be abusive and paranoid.
That kind of rough pranking is an abomination to God. That’s not the way it’s done in Heaven. Making a laughingstock of someone is closer to how the Devil does business. There are plenty of other forms of humor quite appropriate to faith, but lying to someone who trusts you, for any reason at all, is not from God.