What does Matthew 21:31 mean?
After defusing their attempted trap (Matthew 21:23–27), Jesus has asked some chief priests and elders another question, this time about a parable (Matthew 21:28–30). He has described two sons whose father separately instructs them to go work in the vineyard.The first son is openly defiant, telling his father he won't obey. Later, however, he changes his mind and does exactly as he was told. The second son gives the polite, seemingly obedient answer, but never actually does what his father commanded.
Here Jesus asks these religious leaders His question: Which son did his father's will? They answer the only way they can: The son who did the work, even though he first said no, is the one who did the father's will. The father wanted action, not just words. The one who acted obeyed. Despite the first son's initial rudeness, his change of heart meant he came to obey and honor his father. The second son, on the other hand, never really honored his father, as proven by the fact that he only talked about obedience—he did not actually obey (John 14:15).
Now Jesus lowers the boom. His statement would have landed like a slap in the face. The examples of prostitutes and Jewish men who collected taxes for the Romans were not random choices by Jesus. Combined, these stereotypes summed up the worst of the worst in Israel's sense of religious purity: wretched, wicked, traitorous, dirty, and despicable. In fact, they were considered outsiders to Israel's religious community. They were lower than nobodies.
And yet, Jesus is claiming those very people would enter God's kingdom ahead of the most religious and powerful men in Israel. The parable just given, further explained in the next verse (Matthew 21:32), shows Jesus is still talking about belief in the message of John the Baptist. Many prostitutes and tax collectors believed and repented—moving from defiance of God to submission (1 Corinthians 6:9–11). The Jewish religious leaders would merely pretend to submit, but never really obey (John 5:39–40; Matthew 23:27).