What does Matthew 21:26 mean?

Jesus has agreed to answer a pointed question from a group of chief priests and elders on one condition: They must answer His question first. He has asked them whether the work of John the Baptist was from heaven or from man (Matthew 21:23–24). Their question, as posed, was legitimate. However, their motives were not: the men who challenged Christ were not sincerely seeing an answer, but an excuse to catch Jesus saying something that would make Him guilty of blasphemy.

With Jesus' counter-question, those hypocritical leaders are now stuck. If they say that John's baptism was from heaven, the obvious implication is that they're disobeying God. Of course, that's not what these priests and elders think, but here they admit they are afraid to tell the truth. John the Baptist was popular with the people. The crowds of Israelites who flocked to see John and be baptized by him believed the man was a legitimate prophet sent from God.

In admitting this, even to each other, these priests and elders will reveal just how dishonest and political they really are. Jesus knew this, of course, when He posed the question to them. In a way, His response was, in fact, an answer to their original challenge. If Israel's religious leaders had believed John was a true prophet from God, they would have believed his message about the Messiah, whom he identified as Jesus.

These men have an opportunity, of sorts, to at least demonstrate integrity. The honest answer—albeit the unpopular one—would be to say they thought John the Baptist was not from God. And yet, their first commitment is not to the truth but to their own security. It's the same reason they refuse to see that Jesus is the Messiah. Jesus has trapped them in this moment behind the wall of their own dishonesty and unbelief. Their public response will make this clear (Matthew 21:27).