Peter is probably the best known disciple of Jesus. He had a big heart and a big mouth. When Jesus went back to Heaven, he was left in charge of the church. As the movement grew, so did the troubles, and eventually Peter got so much heat that he had to run from Jerusalem.
Near the end of his live, he writes a letter for all the new churches in the Empire, who are also facing oppression and persecution. He talks about embracing their new identity as followers of Jesus, and how to suffer well.