Apparently Festus was troubled by Paul’s case; here was this guy Paul who had done nothing against Roman law, being held in his jail. He had been accused of terrible crimes by the Jewish authorities in Jerusalem, the only problem was they never quite mentioned what those crimes were, and it seemed to Festus that it came down to a doctrinal dispute of some kind that they couldn’t or wouldn’t quite make clear to him. Although he wanted to free Paul, he also wanted to keep the Jewish authorities on his side; he wasn’t sure what to do, except that Paul had exercised his right as a Roman citizen to appeal the matter to Caesar. Ah yes, there was an exit for Festus, just ship Paul off to Rome and let the bigwigs deal with him; yet this seemed to bother Festus.
When King Agrippa was in town for several days, Festus discussed this troubling case with him, found that Agrippa was quite interested and desired to hear from Paul himself. It would seem that Agrippa was much more familiar with Jewish custom and practice; he may have known about Paul before coming to visit Caesarea.
Their audience with Paul takes up the entirety of chapter 26. Paul takes them through his testimony from childhood to the present day, as we have seen him do previously, yet most any lawyer would tell you that Paul made a mistake in doing so:
Festus said: “King Agrippa, and all who are present with us, you see this man! The whole Jewish community has petitioned me about him in Jerusalem and here in Caesarea, shouting that he ought not to live any longer. I found he had done nothing deserving of death, but because he made his appeal to the Emperor I decided to send him to Rome. But I have nothing definite to write to His Majesty about him. Therefore I have brought him before all of you, and especially before you, King Agrippa, so that as a result of this investigation I may have something to write. For I think it is unreasonable to send a prisoner on to Rome without specifying the charges against him.” (25:24-27)
Following this, Paul fills the whole chapter (26) with his narrative. All Paul needed to do was say that he had no idea what the Jews were accusing him of for he had done no wrong, and Festus is trapped by his own words; Paul should have withdrawn his appeal to Caesar and gone free. By talking more than that, there is always the chance that they find something to charge him with, so just shut up!
But Paul wasn’t trying to be set free, for he knew that God had another mission for him, this time in Rome (23:11).
In giving his testimony, Paul proclaimed the Gospel to all of the people in the room as Festus noted: “Do you think that in such a short time you can persuade me to be a Christian?” (26:28b). At the end of the day, Festus and Agrippa agreed that Paul could be set free, except for his appeal to Caesar (26:30-32). Paul will be sent to Rome as soon as it can be arranged.