The Bible states that the apostle Paul kept the Sabbath day, as his custom was (Acts 17:1-3). In Corinth, where Paul labored a year and six months, he “reasoned in the synagogue every Sabbath, and persuaded both Jews and Greeks” (Acts 18:4).
At Antioch and Philippi, Paul observed the Sabbath and taught in the synagogues on that day (Acts 13:14; 16:12,13). At Antioch, “the Gentiles begged “that these words might be preached to them the next Sabbath…On the next Sabbath almost the whole city came together to hear the word of God” (Acts 13:42-44).
When Paul and Silas came to Philippi, a Gentile city in Greece, there was no synagogue but it did not stop them from worshiping on the Sabbath: “And on the Sabbath day we went out of the city to the riverside, where prayer was customarily made” (Acts 18:4).