What does Acts 12:1 mean?

While Barnabas and Saul spread Jesus' story in Syrian Antioch, the church in Jerusalem is facing perhaps its greatest threat since Saul (Acts 9). Josephus explains that Herod Agrippa I is the grandson of Herod the Great and the son of Aristobulus. He spent his formative years in Rome, first under the protection of Tiberius and then getting into trouble and regularly allowing his wife, Cypros, to bail him out. He switched allegiances to Caligula and was only saved when Tiberius died and Caligula was made Caesar. Caligula made Agrippa king of Philp the Tetrarch's territory, northeast of Galilee. Agrippa He arranged for the exile of Antipas—the self-styled Herod who killed John the Baptist—and gained Galilee and Perea, across the Jordan River from Judea and Samaria. Agrippa endeared himself to the Jewish leadership when he convinced Caligula to refrain from installing a statue of himself in the temple. In AD 41, Caligula was assassinated, Claudius became Caesar, and Agrippa gained Idumea, Judea, and Samaria, making him the most powerful king in the area since Herod the Great.

Whether because he was politically savvy or because he saw genuine worth in Judaism, Agrippa is supportive of the Sanhedrin and lives in Jerusalem, not the capital of Caesarea Maritima on the coast of Samaria. The Mishnah says he read the Mosaic law to the people in accordance with Deuteronomy 31:10–13. When he got to Deuteronomy 17:15, which says, "You may not put a foreigner over you, who is not your brother," the people would reassure him that he was their brother.

Violently arresting Jesus-followers would strengthen the loyalty of the Sanhedrin to Agrippa even more. The Sanhedrin persecuted the church in Jerusalem, somewhat inconsistently, since its inception (Acts 4:1–22; 5:17–42; 6:8—7:60) until a young Pharisee-in-training named Saul drove many of the lay-members out of the city (Acts 8:1–3). But Saul met Jesus, and the church and the Jewish leaders have been in relative peace since (Acts 9). Although Agrippa's actions represent an escalation in hostilities, and deaths will increase, the church will remain strong.