Acts 12 is the last chapter of the book of Acts that places the apostles, specifically Peter, in the center of the narrative. The church is well-established in Jerusalem and deepening its base in Judea and Samaria. Already, Gentiles are coming to Christ in the coastal city of Caesarea Maritima and far north in Syrian Antioch. It is almost time for the gospel to spread further.
Acts 12:1–5 provides the only explicitly recorded account of an apostle's death in Scripture. Church tradition claims to know when and how the others died. For example, Peter was reportedly crucified upside-down, and John survived being burned in boiling oil and died of natural causes. Biblically, however, we only know for certain about James, the brother of John and son of Zebedee (Mark 1:19–20). According to Josephus' writing, Herod Agrippa I was one of the few of Herod the Great's descendants who understood and catered to Jewish religious leadership. Here we see Herod Agrippa I arrest and behead James, and then imprison Peter.
Acts 12:6–11 records Peter's dramatic rescue. Peter is in prison in Jerusalem—probably in the Fortress Antonia—chained between two soldiers, when an angel appears and tells him to get up. The chains fall off, and the angel reminds Peter to get dressed. He does so and follows the angel past several guards and into the city. The angel disappears and Peter finally realizes he's not dreaming.
In Acts 12:12–19, Peter rushes to the home of Mary, the mother of John Mark and possible owner of the upper room. Several Jesus followers, apparently not apostles, are there praying for Peter's release when they hear a knock. A servant girl named Rhoda answers but is so overcome with excitement she leaves him outside as she runs to tell the other Jesus-followers. After arguing as to whether it is really Peter, they let him in, and he explains what has happened. Peter tells them to relay the story to James, the half-brother of Jesus and leader of the Jerusalem church, and the other church leaders, before going into hiding. Peter will appear only once more in the book of Acts, in chapter 15 where a council of leaders determines if Gentile Jesus-followers should be required to follow the Jewish law.
Acts 12:20–25 describes the death of Herod Agrippa I, grandson of Herod the Great. Ancient historians such as Josephus indicate that it was during a disagreement with Tyre and Sidon, on the second day of the games Agrippa I is hosting for Caesar in Caesarea Maritima when he enters the arena and gives a speech wearing a robe made with silver thread. The sun catches the silver making him glow, and the people cry out, "The voice of a god, and not of a man!" (Acts 12:22). While it seems at another time Herod Agrippa I might have had the humility to deny their praises, this day he accepts them. An angel strikes him down. According to ancient historian Josephus, Agrippa's death involved five days of excruciating pain from an undiagnosed ailment that involved internal worms.
In contrast, the church is growing. Despite James' death and Peter's arrest, the church is spreading. Barnabas and Saul deliver the support the church in Syrian Antioch collected for the church in Jerusalem (see Acts 11:27–30), update the church leaders, and return to Syrian Antioch. At the end of Chapter 12, the focus of the Book of Acts transitions from the apostles to Saul of Tarsus. Soon to be the Apostle Paul.