At the end of chapter fifteen Paul had a disagreement with Barnabas and they headed off in different directions. In 16:1, Paul and Silas arrive in Lystra where we are introduced to Timothy who will become a very important person in the Church. Timothy’s mother is Jewish but his father is Greek and therefore he would not have been circumcised. In order for Timothy to work among Jews Paul circumcised him (16:3). This seems ironic given that they are delivering the letter written in Jerusalem but then this is the apostle who was willing to become like either Jew or Gentile that he might save them (1 Cor 9:20ff).
Later in chapter sixteen they are jailed and although they could have escaped thanks to an earthquake, they remain to convert the jailer and his family. We also learn the power of Roman citizenship (16:38). The authorities are forced to appease them once they learn that they are Roman citizens because you cannot beat and jail a citizen without a trial.
Paul arrives in Athens and uses a local altar and quotes from philosophers to get their attention. Some were confused, thinking that he was proclaiming two gods: Jesus and resurrection (17:18). Others scoffed when they realised that he was claiming that people would rise from the dead (v32). Some did believe, possibly Gentiles as they have Greek names. Paul then travelled to Corinth and God assured him that it was safe to preach there (18:9). Paul stayed there for 18 months and the local proconsul was not interested in appeasing the Jews so they were forced to leave the Christians alone (and beat their synagogue leader instead).
In Ephesus, a Greek-Jew named Apollos was trained by Priscilla and Aquila and proceeded to “refute the Jews in public debate, proving from the Scriptures that Jesus was the Messiah (18:28). This demonstrates that it was important to prove from the Scriptures that Jesus was the Jewish Messiah (cf. 9:22; 17:3). It also shows that scholars such as EP Sanders are wrong when they say that for Paul the only thing wrong with Judaism was that it is not Christianity. If it is true that Jesus is the Messiah, something believed by Apollos, Paul, and others then to reject Jesus is to reject Judaism. Jesus, all of the apostles, and most of the other leaders mentioned in Acts are Jews. They believed that the Messiah is the sine qua non of Judaism and they believed and taught that Jesus was that Messiah. To reject Jesus, is to reject the Messiah, is to reject the Scriptures which prove that he is the Messiah.