Physicians can cure many illnesses, both physical and mental. But only Jesus can bring about the healing that makes bad people good.

A noted psychiatrist recognized his own limitations in a conversation he had with British clergyman William Barclay. "All that a psychiatrist can do," said the doctor, "is strip a man naked until you get to the essential man; and if the essential man is bad stuff, there's nothing you can do about it. That's where you come in." Barclay later commented, "I think he meant that this is where Jesus comes in."

Zacchaeus was a bad man who needed inner healing. As a chief tax collector, he could take a cut from what his subordinates had collected. Therefore he was a wealthy man. Apparently he had heard about Jesus and wanted very much to see Him. Being short in stature, he climbed up into a tree to see above the crowd.

I believe Zacchaeus was overwhelmed with guilt when Jesus looked up and told him He was coming to his house. Later, he told Jesus he would give half his wealth to the poor and restore fourfold to any he had defrauded. Jesus said, "Today salvation has come to this house" (Luke 19:9). In that instant Zacchaeus was spiritually healed. Only the ultimate Physician can make bad people good.
  — Herbert Vander Lugt