What is the meaning of countrymen?

The meaning of countrymen (Greek: συμφυλετῶν/sumphuletōn) is disputed. The word is very rare, appearing only once in the New Testament and very infrequently outside the New Testament. It could have one of two possible meanings: either people of the same ethnic group or fellow-inhabitants (of a city or region). The key to finding the correct meaning is noticing that Paul correlates the experience of the Thessalonians with the experience of the churches in Judea. Rather literally, we can represent Paul’s statement like this:

. . . you yourselves suffered the same things from your own countrymen

           just as (Greek: καθώς/kathōs)

they [suffered] from the Jews.

This correlation indicates that your own countrymen bear the same relation to the Thessalonians that the Jews bear to the Jewish Christians in the Judean churches. Clearly, the Jewish Christians of Judea shared the same ethnicity as the Jews who persecuted them, and this leads to the conclusion that, in using the word countrymen, Paul was speaking about the Gentiles of Thessalonica, who shared the same ethnicity as the Thessalonian Christians—the majority of whom were Gentile, as indicated in 1 Thessalonians 1:9.^1,2