King Herod is reported to have begun a new wave of persecution against the Church. We have to be very careful of who we think of as 'King Herod': Herod the Great reigned from 41 to 1 BC, he is the Herod of Matthew 2-the slaughterer of the innocent, he was married TEN times; Herod Philip 1, the first husband of Herodias; Herod Antipas, the second husband of Herodias, killer of John the Baptist and to whom Pilate sent Jesus at His trial; Herod Agrippa, who is the Herod mentioned here. There were other King Herod's!
This King was popular with the Jews as he observed the Jewish Law and that was likely to be the reason why he attacked the Church. Even his arrest of Peter demonstrates his desire to pacify the Jews, as the Law decreed that no trial or execution should be carried out during the eight days of Passover.
The Church was under threat like never before: James, one of the Twelve and one of the three-along with Peter and John most intimate with Jesus-is martyred and it appeared that Peter was heading the same way. It must have appeared that nothing could stop King Herod and yet Peter is rescued from prison supernaturally and there is a slightly humorous scene when he returns to the house of Mary, the mother of John Mark, where he is left waiting at the door whilst the maid runs around telling everyone that he was at the door! However, such a powerful answer to prayer has to elicit shouts of joy! Now the James to whom Peter refers here is the one who was brother of Jesus, and we can note that he is now the leader of the Church. Although it appears that James did not support his brother when Jesus was alive, we are told in 1 Corinthians 15 v 7 that the risen Christ made a specific appearance to him. The death of Jesus did for James what His life had somehow not.
It appeared that Herod was able to do whatever he liked, but he was opposing God and we are informed at the end of this chapter that Herod dies in the most horrific way. The last verse of chapter twelve brings the reader full circle from the end of Acts eleven. Barnabas and Paul have completed their journey to Jerusalem, but have brought with them John Mark, who will prove to be the one who breaks their relationship.