What does Acts 16:20 mean?
Roman rule succeeded, in part, because it left many aspects of a conquered territory untouched. Local custom, language, and religion were mostly tolerated. In other ways, the Roman Empire had a tight rein on its inhabitants. They required rigid adherence to certain laws and considerable taxes. Most who lived under Roman rule were slaves or subsistence workers. But people knew how to game the system. Rome expected a lot from the local rulers they appointed. The reason the Sanhedrin could convince Pilate to crucify Jesus, for instance, was by threatening to accuse Pilate of sedition (John 19:12) or through provoking a riot (Matthew 27:24).In this verse, we see the owners of a possessed slave girl make a similar play against the magistrates of Philippi. They don't care that Paul, Silas, Timothy, and Luke are teaching the people that some Jewish man is God. They're not actually offended at claims that Jesus offers forgiveness from sins and reconciliation with God. They care that Paul expelled the demon from their slave girl, and now she can't make them money telling fortunes (Acts 16:16–19). Their complaint uses the Roman law to get revenge.
The Roman Empire made room for many gods, but all had to be authorized by the government. Even Judaism was authorized—though the Romans referred to Jews as "atheists," for rejecting all but one, invisible God. In this verse, the owners of the slave girl claim Paul's team is causing a disturbance because they are "[advocating] customs that are not lawful for us as Romans to accept or practice" (Acts 16:21). That is, they are teaching that Jesus is God, and Jesus is not one of Rome's approved deities.
Though Judaism wasn't illegal, spreading it was considered against the common good as it drew people away from worshiping the emperor. The slave girl's owners get what they want: the magistrates beat Paul and Silas and throw them in jail. But by characterizing the two men as "Jews," they make a terrible mistake. Paul and Silas are Jews, but they are also Roman citizens (Acts 16:37). To beat and imprison a Roman citizen without a trial was almost worse than to introduce a new deity. The magistrates have unknowingly violated the missionaries' civil rights, and Paul will be sure the error does not go unnoticed (Acts 16:37).
