“On the day set for their meeting, Herod, robed in pomposity, took his place on the throne and regaled them with a lot of hot air. The people played their part to the hilt and shouted flatteries: “The voice of God! The voice of God!”
That was the last straw. God had had enough of Herod’s arrogance and sent an angel to strike him down. Herod had given God no credit for anything. Down he went. Rotten to the core, a maggoty old man if there ever was one, he died.”
(Acts 12:21–23 MESSAGE)

I like the way Eugene Petersen paraphrases Acts 12.23 and the story of the death of Herod:  “Down he went.  Rotten to the core, a maggoty old man if there ever was one, he died.”

This was Herod Agrippa I, grandson of Herod the Great (murderer).  He had James the son of Zebedee killed and he had Peter locked up behind two doors in a Roman prison awaiting his “trial” before the crowds.  Surely he had the whole Christian movement on the run.  In a moment, much like the wicked Haman in Esther, the tables are turned.  Peter is freed by supernatural means and Herod later is struck with worms and dies a horrible death.

It is not a mistake that Luke writes immediately after Herod, opposer of the Christian faith’s death: “Then God’s message flourished and multiplied.” (Acts 12:24 HCSB).

The one who would arrest and execute Christians was dead.  The word of God went on flourishing and multiplying.  This is the power of God.