Take a look at Acts 16: we're reading about two men, Paul and Silas, who were some of the first missionaries who went from city to city spreading the gospel. Paul and Silas were focused on telling people that Christ died, was buried, and was resurrected so that through faith in Jesus and his work they could receive forgiveness and eternal life.
This is exactly what they are doing in a place called Macedonia when we pick up the story in verse 20. A lot of people in Macedonia didn't like Paul and Silas' message and their actions, and so they brought the two before the authorities of the city to try and charge them with crimes. Take a look at what happens:
20 They brought them before the magistrates and said, “These men are Jews, and are throwing our city into an uproar 21 by advocating customs unlawful for us Romans to accept or practice.”