Great Persecution & Missional Moment

So Stephen is stoned to death and a great persecution breaks out against those who are following Jesus in Jerusalem. Only the Apostles and the men and women arrested by Saul remain in Jerusalem. The rest are scattered throughout Judea and Samaria. And here is the kicker..."they all become missionaries announcing the message of Jesus." What is this message? What God can turn a great persecution into a missional moment?