As in the ministry of Jesus, the gospel sometimes threatened existing business interests (see also 19:25–27; Mark 5:1–20). Those who were exploiting the slave girl attacked the Christian missionaries and dragged them to the authorities as criminals. They blamed them for causing trouble, used racial bias ("These men are Jews"), and appealed to the Philippians’ pride ("us Romans"). The Philippians were proud Roman citizens of a Roman colony.
customs that are unlawful: By law, Jews were not permitted to make converts of Romans.