Luke 19:5 When Jesus came by, he looked up at Zacchaeus and called him by name. “Zacchaeus!” he said. “Quick, come down! I must be a guest in your home today.” 6 Zacchaeus quickly climbed down and took Jesus to his house in great excitement and joy. 7 But the people were displeased. “He has gone to be the guest of a notorious sinner,” they grumbled. 8 Meanwhile, Zacchaeus stood before the Lord and said, “I will give half my wealth to the poor, Lord, and if I have cheated people on their taxes, I will give them back four times as much!”
Zaccheus was a Jewish descendant, who was employed by the Roman government to collect taxes. It also says he was "rich", which probably meant he had overcharged taxes to make a profit for himself. As such, he was hated by the Jews and explains why the Jewish people were so displeased that Jesus invited himself to his home.
This parable is only told in Luke, and reaffirms Luke's desire to show how Jesus reached out to lost sinners discarded by the society, and in this case the Jews. We might call Zaccheus a "seeker", much like Nicodmeus, in the gospel of John. Being a guest in someone's home was a gesture of intimacy and hospitality in the middle Eastern culture. For Jesus to enter a "sinner's" home would have been unspeakable to the Pharisees and other Jews.
But the most important part of the parable is Zaccheus' response to Jesus' invitation to be a guest in his home. Zacchaeus says publicly that he would give half of his riches to the poor and pay back four times those he had cheated. We call this repentance, meaning to turn from one's sin to trust in Jesus. Repentance in this case was supported by his re-paying those he cheated, and giving half of his riches to those in need. Repentance is a sign of faith in action and obviously highly thought of by Jesus.
Further, Jesus responds by saying, "Today salvation has come to this home for this man has shown himself to be a true son of Abraham." It is Zacchaeus' faith that saves him, and is evidenced by his willingness to give up his previous lifestyle to follow Jesus. But notice it is Jesus who reached out to Zacchaeus and went to his house. The parable ends by saying, "the Son of Man came to seek and save the lost."
If Jesus cared so much about lost sinners to invite himself into their homes, are willing to meet lost people in their "proverbial homes"? And, in fact, Jesus reached out to us before we could respond in faith and repentance. It is Jesus' non-judgmental invitation to be with us that fuels us to be equally hospitable. Who is a Zacchaeus in your life? Maybe it is someone you hate. Pretty radical to think of inviting them to anything isn't it? Maybe we need to repent of our Pharasaic like attitude to the "tax collectors" in our society.