Jesus had just said that morally wicked people who repent are welcomed by God, but religious hypocrites (who see no problem with their duplicity) are not (Matthew 21:28-31). It was a strong conclusion. In today's verse, Jesus continued His rebuke. He pointed back to John the Baptist (Matthew 21:25-27), whose ministry was valued by the crowds but despised by the religious leaders, and Jesus declared that John had said what was right.
 
John had simply declared that God was coming and that people needed to get ready; which meant that they needed to be right before God. The only way to do that was to admit that they were unrighteous, and then repent and seek forgiveness. By contrast, the top religious clerics did not think they were guilty before God at all. They did not believe his message and so did not believe that they had need to repent (Matthew 3:7-10).
 
The fraudulent tax officials and women of the night knew that they had a moral problem. They were openly despised and knew that nobody really loved them. But when Jesus came and was willing to spend time with them and show them genuine and pure love, they saw the person John had spoken about, and they believed in Him. They knew they had been forgiven so that they could start to follow the way of righteousness.
 
It is easy to talk about righteousness, but the words have no authenticity until it is done. God-given faith is as necessary to believe the bad news about our unrighteousness, and repent, as to believe the gospel and learn to become a disciple of Jesus. On the other hand religious hypocrisy does not need any faith, just a conviction that as long as the acting can be sustained, God will be impressed. But God does not play drama games. He is looking for honest relationships where sinners admit it and repentant people are willing to learn the way of righteousness. If that is you, be encouraged: but if you are acting, you are in a spiritually dangerous place. Repent!