I think the first thing we need to do is to consider the context. It is repeated that Jesus is now on His way to Jerusalem (17:11; 18:31; 19:11, 28, 41). In Luke 18:31-34 Jesus tells His disciples that He will fulfill prophecy by being rejected, put to death, and resurrected. What takes place in Jericho (with Zaccheus), then, must be related to our Lord’s ultimate goal of going up to Jerusalem to die. On the way to Jericho, Jesus healed the blind man. This was another proof that He was the Messiah (see Luke 4:18). It also caused the crowds to praise God, and to think well of Jesus.
The healing of the blind man happened just outside Jericho, as Jesus approached. The incident with Zaccheus happens in Jericho, as Jesus is passing through. Surely word of the healing of the blind man spread quickly, so that the crowds began to gather as Jesus passed through the city of Jericho. It was something like the triumphal entry would be in Jerusalem, in that Jesus would be enthusiastically received. But the crowds are fickle here, as they will be in Jerusalem. Those who hailed Him as the coming King were later those who cried out for His death. Our Lord’s dealings with Zaccheus quieted the praise of the crowds, and prompted their protests (see Luke 19:7 “They all began to grumble, saying, ‘He has gone to be the guest of a man who is a sinner.’”)
Notice, it was not Zaccheus who invited Jesus to his house for a meal. Zaccheus was trying to see Jesus, and perhaps to avoid the crowds as well. They did not like tax-gatherers. Indeed, he was a “chief tax-gatherer” (verse 2). Jesus looked up into the tree and saw Zaccheus. Jesus knew this man’s name, and called him by name, and then invited Himself to his house for a meal. Zaccheus was delighted, of course, but the crowds were very unhappy about this. Why? Because they considered Zaccheus to be a great sinner—and so he was.
All of this raises an issue which is at the heart of our Lord’s ministry, and which is the key to His rejection as well. In Luke 4:16, Jesus comes to the synagogue in His home town of Nazareth. He reads from Isaiah 61:1-2 and informs His audience that He is the fulfillment of this messianic prophecy. The people rejoice, until Jesus makes it clear that He has come to save sinners, including the Gentiles. That is too much for them, and now they seek to kill Him (Luke 4:22-31). It is this same issue of Jesus coming to associate with and to save sinners which arises early in Mark’s Gospel (Mark 2:13-17), and it centers around another tax-gatherer, Levi.
Now, back to Luke 19. Jesus approaches Jericho and on His way heals a blind man. This is proof that He is Messiah, and the crowds love it. But when Jesus carries out His ultimate messianic mission—saving guilty sinners—this is too much, and the praise of the crowds turns to protest. After this incident with Zaccheus, and while the same crowds are listening, Jesus tells a parable which warns them about their stewardship. The warning is about the failure to make use of that which God has given to us. I believe that the ultimate treasure He has given is the good news of the Gospel. So far as saving sinners is concerned, the Jews wanted to “bury” this, rather than to have to think about associating with those who were known to be sinners in the past.
Now, as to relating this story to little children. I think the story is quite simple. It is one of the “Sunday school stories” that every child seems to be familiar with. The story certainly indicates to us that God chose to associate with (and to save) this man whom He knew to be an unworthy sinner. The others were angry, because they did not see themselves as sinners, but as the righteous (this contrast is clearly made by Luke in Luke 17:9-14). Children need to see from this story that Jesus came to save those who are unworthy, those who are sinners. That is the message of the Gospel.
Children can be very cruel about who they will play and associate with. They often shun children who are different, dirty, or whom they have been told are “bad” in some way. They should have no difficulty in grasping the concept that Jesus came to be with those whom others didn’t like. Jesus came to save those who are unworthy sinners. What could be better news than this?