It's not really about children or being like them in any emotional or physiological sense. Let's consider a tale of a grape grower and his hired hands:
For the kingdom of heaven is like a master of a house who went out early in the morning to hire laborers for his vineyard. After agreeing with the laborers for a denarius a day, he sent them into his vineyard. And going out about the third hour he saw others standing idle in the marketplace, and to them he said, ‘You go into the vineyard too, and whatever is right I will give you.’ So they went. Going out again about the sixth hour and the ninth hour, he did the same. And about the eleventh hour he went out and found others standing. And he said to them, ‘Why do you stand here idle all day?’ They said to him, ‘Because no one has hired us.’ He said to them, ‘You go into the vineyard too.’ And when evening came, the owner of the vineyard said to his foreman, ‘Call the laborers and pay them their wages, beginning with the last, up to the first.’ And when those hired about the eleventh hour came, each of them received a denarius. Now when those hired first came, they thought they would receive more, but each of them also received a denarius. And on receiving it they grumbled at the master of the house, saying, ‘These last worked only one hour, and you have made them equal to us who have borne the burden of the day and the scorching heat.’ But he replied to one of them, ‘Friend, I am doing you no wrong. Did you not agree with me for a denarius? Take what belongs to you and go. I choose to give to this last worker as I give to you. Am I not allowed to do what I choose with what belongs to me? Or do you begrudge my generosity?’ So the last will be first, and the first last. (Mt 20:1-16)
All those who accepted the Lord’s invitation to the vineyard started at the same place there; they started as equals, no matter their stations in the outside work-a-day world. Out in that world, a wealthy landowner could command a multi-faceted engine of commerce. Also out there was a pauper who lived day to day. Their ranks differed in that world, but in the kingdom, the two were equals. In the kingdom, the one did not exert control or authority over the other. Tenure and seniority in the world counted for nothing in the kingdom. In fact, rather than complain that a newcomer in the kingdom had all the advantages from God that a veteran had, the veteran rejoiced that the newcomer had even entered in the first place. That was the spirit of fraternity and equality that permeated the holy household.
In an everlasting kingdom, this frame of mind obviously still applies. The new believer indeed enters the kingdom without any assumptions about it or plans for it and is eager to explore it openly and more deeply without any preconceived notions about it or designs on it. Like a child he receives the kingdom of God and is no less valuable in it than the seasoned believer is. “Let the children come to me, and do not hinder them,” Jesus said. “For to such belongs the kingdom of God. Truly, I say to you, whoever does not receive the kingdom of God
like a child shall not enter it” (
Lk 18:16-17, emphasis added). This attitude of humility does not visit violence on the kingdom; instead, it brings acceptance and belonging to it.