The book of Acts includes several instances of Christian leaders attending Jewish Sabbath services to share the gospel with those in attendance. Examples include Acts 13:43; 14:1; 16:14; 17:4, 17; and 18:4. These passages mention the presence of religious Gentiles as well as Jews, leading some to believe that Christian and Jew alike celebrated the Sabbath on the same day. Otherwise, why would Gentiles be participating in the Saturday Sabbath?
At first, this had been my conclusion as well. After digging deeper, however, I realized that, in order for us to really understand who these non-Jewish worshipers are, we need to understand the different types of Gentiles the New Testament deals with. There are at least three groups:
- Gentile believers
- Gentile unbelievers
- Greek proselytes—i.e., Gentile converts to Judaism (divided by some into two sub-groups: “proselytes of righteousness” and “proselytes at the gate”; the former were more fully integrated into Judaism than the latter)
(For more information on Greek proselytes, see here and here.)
When they mention non-Jewish synagogue attendees, the above Sabbath passages in Acts are referring to Greek proselytes. These Gentile adherents to Judaism were bound to certain Mosaic laws and customs—including the Jewish Sabbath. The Greek proselytes are noted as being “devout” (Acts 13:43; 17:4), and the New Testament even describes them as fearing God (10:22) and worshipping God (16:14). Paul uses this terminology in the synagogue in Antioch when he addresses both the Jews and proselytes: “Men of Israel [Jews], and you who fear God [Greek proselytes], listen” (Acts 13:16).
In Acts 14:1, we see a “great multitude” of Jews and proselytes believing in the gospel. When Paul preaches in the synagogue at Thessalonica for three Saturdays in a row, many are persuaded, including “a great multitude of the devout Greeks” (Acts 17:4). We are told in Acts 17:17 that when Paul visits the synagogue in Athens, he reasons with two groups of people: the Jews and the Gentile proselytes. Once again, in the synagogue at Corinth, Paul repeatedly preaches the gospel to “both Jews and Greeks” (Acts 18:4).
In each of these circumstances, we see a blatantly evangelical intent on the part of Paul and the other Christians. They are not preaching to fellow believers. They are visiting the synagogues to minister to the Jews and proselytes, not to celebrate the Saturday Sabbath with them.