"Zaccheus was a wee little man..." What do we really know about Zaccheus?
He is described as being a "chief tax collector" in the district of Jericho, and was rich. This indicates that he was smart, probably reasonably well educated, and good at his job. However, tax collectors in that culture were loathed and distrusted, as they had a reputation of being political clients of the Roman imperial government, not religiously observant, and financially corrupt. And of course the observant, religious folks enjoyed looking down on those who were thought to be less observant of the Law, and who associated with people who were not Jews and especially with occupying imperialists.
Jesus was less likely than most people to judge individuals by their reputation. One chapter earlier, (Luke 18:9-14), Jesus tells a story of two men praying in the Temple: one, a high ranking member of the religious establishment and totally convinced of his own righteousness, telling God how observant and worthy he was. The other was a tax collector, assumed by most people--including the "righteous" man--to be unrighteous, unobservant, and unworthy. However, Jesus' judgment was different. God is not impressed with the self-described righteous, but honors the man who admits he is a sinner and throws himself on the mercy of God.
Luke also tells the other side of the coin (Luke 18:18-24), with his story of the "Rich Young Ruler". This young man also claimed to be totally righteous. Jesus told him that there was "one more thing needed": he needed to give away his wealth and follow Jesus. Again, Jesus is not impressed with claims and wealth; He is concerned about attitudes and obedience.
Zaccheus here is the next one in this line.(Luke 19:1-10) He obviously knew something about Jesus; he may even had heard John the Baptist's preaching--which had been in the Jericho area. Luke tells us that even publicans--tax collectors--came to John to be baptized, and for advice. John's answer: Collect no more than what is required. And Zaccheus may have been one of those. In this light, look at Zaccheus' statement to Jesus: "I give half my income to the poor"--the literal translation is present tense, that he is actually doing this routinely; and "If I have defrauded anyone, I refund four times the overcharge"--again, present tense. (Think about it--if a significant part of his income was obtained through overcharges, he couldn't make those refunds.) Jesus recognizes Zaccheus as being saved, and being a legitimate "son of Abraham" . And BTW, the name Zaccheus means "pure" or "innocent".
There is an early church tradition that Zaccheus became part of Jesus' group of followers, and eventually became the Bishop of Caesarea. And there is to this day a tree in Jericho that is reputed to be the original tree that Zaccheus climbed.
The obvious moral of the story is that Jesus has come to "seek and save those who are lost". Beyond this, it is also a reminder that Jesus sees people differently that we do; that we tend to judge people by the labels put on them by society, which is not necessarily just nor accurate. Jesus saw the rich young ruler as arrogant and selfish; he saw Zaccheus as what his name meant: pure-hearted.