Let's look at this story of Zacchaeus. Previously, in Luke chapters 14 and 15, we see the Pharisees and scribes coming against Christ because He engaged sinners and ate with them. The Pharisees were men of extreme purity of life and because Christ engaged sinners, and ate with them it made the Pharisees afraid of Him. However, Christ was in the midst of the sinners for one reason and that was to save them.
In Luke 19:9-10 it is Jesus answering Zacchaeus. In the story of Zacchaeus we have an illustration of Jesus Christ doing the work as Savior. He declared that He came to seek and save those that are lost, those that are without God.
According to the story, there was a crowd and Zacchaeus wanted to see who was causing it. Zacchaeus climbed the tree to see who Jesus was (Luke 19:3). Just like today we are curious as to who is causing a crowd to gather, so was Zacchaeus in his day. At this time Zacchaeus was a tax gatherer for the Romans and he was rich. A Roman tax gatherer had a district to work and if he exacted nothing more than his wages, he would never become a rich man (Luke 3:13). Zacchaeus was a rich man meaning he exacted more than his wages and this meant he was a rogue, a dishonest or unprincipled man, or he would not have been able to be rich.
And when Jesus came to the place, He looked up, and saw him, and said unto him, Zacchaeus, make haste, and come down; for today I must abide at thy house (Luke 19:5). Then again people murmured because Jesus had went into the home of Zacchaeus who was a sinner (Luke 19:7). We are not told how long Zacchaeus and Jesus were together but we do know that Zacchaeus was finally getting rid of all of his ill-gotten riches (Luke 19:8). Then, because Zacchaeus had repented, Jesus said salvation had come to this house (Luke 19:9).
Notice that Jesus said in Luke 19:9 “forsomuch as he is the son of Abraham.” One might say that he was already a son of Abraham but Jesus did not recognize his sonship until Zacchaeus did the works of Abraham (John 8:39-40). As for the works of Abraham they are believing in God, having faith, obedience, and walking uprightly.
Then Jesus tells us His mission, “The Son of man is come to seek and to save that which was lost” (Luke 19:10). Jesus was criticized for going to the house of a rogue sinner, but the results show the purpose of Him going into the house of Zacchaeus and eating with a sinner was to seek and to save those that are lost.