The purpose of a parable, which is a sermon delivered in person in its original setting, is to persuade those standing nearby. Who is Yeshua seeking to persuade with this parable? Is he comforting his disciples who are like the first son or is he trying to save the obstinate who are standing nearby to criticize? Is Yeshua offering here real forgiveness?
“28 “What do you think? A man had two sons. He went to the first and said, ‘Son, go and work in the vineyard today.’ 29 The boy answered, ‘I will not.’ But later he had a change of heart and went. 30 The father went to the other son and said the same thing. This boy answered, ‘I will, sir,’ but did not go. 31 Which of the two did his father’s will?” They said, “The first.” Jesus said to them, “I tell you the truth, tax collectors and prostitutes will go ahead of you into the kingdom of God! 32 For John came to you in the way of righteousness, and you did not believe him. But the tax collectors and prostitutes did believe. Although you saw this, you did not later change your minds and believe him.”
(Matthew 21:28–32 NET)
The first son represents the sinners who came to John the Baptist and became followers of Torah and the faithful looking for God’s salvation.
The second son represents the Jewish leaders who said they would follow Torah and wait for God’s salvation, but who are insincere, corrupt, and blind. Their insincerity is proven by their failure to respond to John, the prophet of God.
The young son disrespected his father, but had a change of heart. Yeshua compares him to publicly known sinners, people whose misdeeds are visible as opposed to the hidden evil that is in all people. This young man openly said, “I will not.” He did not hide his lack of devotion to his father.
But he had a “change of heart” (metamelaetheis, μεταμεληθεὶς), which implies both regret and repentance. This brought him forgiveness. Yet the quiet evil of the others — those reputed to be righteous — continued to keep them from the kingdom of God.
Better a known sinner who regrets and becomes enlightened than all the hidden sinners whose misdeeds and ill-will are kept quiet.
Most importantly, and I think Yeshua’s persuasion is aimed at the humble ones listening to him more so than at changing the minds of obstinate opponents, we are assured that God accepts a change of heart. We have to know that “God will not punish forever,” and that he welcomes back every heart that regrets wrong and seeks love.