What does Acts 26:3 mean?
When Festus took the position of governor after Felix, he inherited a problem: Paul. Two years prior, the Sanhedrin had first tried to assassinate Paul (Acts 23:12–15) and then charge him with capital crimes against the Roman law (Acts 24:5–6). Felix knew something of Christianity and realized the charges were unproven and unwitnessed by Paul's accusers. But he didn't want to provoke the Sanhedrin, so he left Paul under house arrest in Caesarea Maritima (Acts 24:22–27).When Festus, likewise, tried to accommodate both the Sanhedrin and Paul's Roman citizenship, he found Paul's patience had run out. Paul appealed to Caesar, and Festus must send him (Acts 25:6–12), but Festus has no charges to send with him. He's asked King Agrippa II and an assortment of Caesarean leaders to help him determine what he should tell Caesar (Acts 25:23–27).
To that end, Paul is giving his testimony—both legally and religiously—primarily to Agrippa, whose great-grandfather was Herod the Great and who has a thorough understanding of Jewish religion and culture. As is customary, Paul begins with a polite greeting, but Paul does not edge into undeserved flattery.
"Customs" is from the Greek root word ethos. It can mean an informal custom, but it also means laws and rites, of which the Jews had many. "Controversies," elsewhere translated "questions," is from the Greek root word zētēma. It refers to debates about the law.
Festus, a Roman, does not perceive a difference between Christianity and Judaism. In fact, Rome will only begin to see a distinction in AD 150 after the Khobar Rebellion. Agrippa understands. He knows that although the Pharisees believe in the resurrection of the dead, the resurrection of a particular man—Jesus of Nazareth—has caused a fierce conflict (Acts 4:18). Prior to his conversion, Paul was more than willing to resolve that argument by exterminating Jesus' followers (Acts 8:1–3; 9:1–2). Now, however, Paul fully accepts Jesus, and the Sanhedrin identifies him as an enemy.