At first glance, we may think that only Gentiles responded to Paul’s preaching on his missionary journeys, but the Bible makes it clear that many Jews became believers as well. Crispus is a prime example.
Crispus was the ruler of the synagogue in Corinth, meaning he was the leading elder over the synagogue. After Paul preached the gospel at Athens, he traveled to Corinth, a very wealthy port city in southern Greece. Following his normal custom, Paul spent several weeks preaching in the synagogue, showing Jews that Jesus was the Messiah.
.
Eventually, however, some of the Jews became angry and abusive toward Paul, leading him to direct his primary efforts toward the Gentiles. Despite the resistance of these Jews, however, Crispus and his entire household believed in Jesus and were baptized—and so did many other Corinthians, presumably including Jews from the synagogue (Acts 18:1–8).
Crispus and his household must have continued on in the faith, because Paul later made reference to him in 1 Corinthians (1 Corinthians 1:14). The city of Corinth had a long and distinguished history, and it was strategically located near the isthmus that connected southern Greece to the mainland. Every two years the Isthmian Games, similar to the Olympics, were held just outside the city. Partially due to the fact that it was a port city, Corinth had become renowned for its immorality, a problem that is reflected in the issues that Paul had to address later in the church.