John Calvin Commentary Acts 26:19

"Wherefore, O king Agrippa, I was not disobedient unto the heavenly vision:" — Acts 26:19 (ASV)

He now briefly explains for what purpose he recounted the history of his conversion: namely, that Agrippa and the rest might understand that God was the originator of all those things which the Jews condemned as sacrilege and apostasy. He speaks to Agrippa by name because he knew that Festus and the Romans did not understand what a heavenly vision meant.

Now, it is apparent that there is nothing in the core of his doctrine that differs from the Law and the Prophets. Through this, the divine message gains greater credibility, by which Paul was commanded to teach nothing but what was consistent with Scripture. Conversion, or turning to God, is joined with repentance, not as some separate matter, but so that we may understand what it means to repent.

Likewise, conversely, human corruption and stubbornness are nothing other than an estrangement from God. And because repentance is an inward matter of the heart, Paul requires, in the second place, works that demonstrate it, according to that exhortation of John the Baptist: Bring forth fruits meet for repentance (Matthew 3:8).

Now, since the gospel calls all those who belong to Christ to repentance, it follows that all people are naturally corrupt and that they need to be changed. Likewise, this passage teaches that those who separate the grace of Christ from repentance unskillfully pervert the gospel.