The Holy Spirit gives Paul the power to obey and he does. Obedience is a choice he makes. In Galatians 1:16 Paul writes, ‘to reveal His Son to me, so that I might proclaim Him among the Gentiles, I did not confer with any human being.’ He made the choice on his own and so do we.
Even with the abundant Grace that surrounded him on the road to Damascus Paul still had to make the choice for himself to obey Christ and preach to the Gentiles until the day he dies. As he speaks, and forwards his attention onto Agrippa, he explains faith– that there is a moment of salvation in Christ within us and then comes the inward and outward holiness. Paul says first repent (salvation) and then turn to God and do deeds consistent with repentance (inward and outward holiness).
God has kept Paul safe as the Romans rescued him from the Jews in Jerusalem who wanted to kill him and he was able to speak on the castle steps. God is keeping Paul safe still. Paul had spoken of his persecution by the Jews as relating to the Hope of the Resurrection. Now he goes one step further in his defense to point out that Moses and the prophets (he does not say the law) said that the Messiah must suffer and be the first to Rise from the dead. And further, the Messiah would proclaim Light to Jews and Gentiles.
Light surrounded Paul and his traveling companions. They fell to the ground. Now as hearers listen to Paul, he knows Agrippa and Bernice are Jewish and understand the prophets and the heightened anticipation among them that a Savior’s time is near. Paul is gloriously proclaiming Christ Resurrected here and has proclaimed Him to many others because he is obedient to the Lord.
“After that, King Agrippa, I was not disobedient to the Heavenly vision, 20 but declared first to those in Damascus, then in Jerusalem and throughout the countryside of Judea, and also to the Gentiles, that they should repent and turn to God and do deeds consistent with repentance. 21 For this reason the Jews seized me in the temple and tried to kill me. 22 To this day I have had help from God, and so I stand here, testifying to both small and great, saying nothing but what the prophets and Moses said would take place: 23 that the Messiah must suffer, and that, by being the first to rise from the dead, he would proclaim Light both to our people and to the Gentiles.” Acts 26:19-23