(Act 18:1) After these things Paul departed from Athens and came to Corinth;
(Act 18:2) And found a certain Jew named Aquila, born in Pontus, lately come from Italy, with his wife Priscilla; because that (Claudius had commanded all Jews to depart from Rome:) and came unto them.
(Act 18:3) And because he was of the same craft, he abode with them, and wrought: for by their occupation they were tentmakers.
(Act 18:4) And he reasoned in the synagogue every sabbath, and persuaded the Jews and the Greeks.
(Act 18:11) And he continued there a year and six months, teaching the word of God among them.
Yes, 72 Sabbaths spent preaching to unbelievers in a service organised by unbelievers. That was not a Christian worship service. In fact, every single such Sabbath gathering mentioned in Acts is of the same type – a NON-Christian service that some Christians were also attending to witness to those who had not yet accepted Christ.
If your local Adventist pastor spent 72 Sundays preaching to Sunday-keepers in a Sunday-keeping church hall, would he be keeping Sunday? No … by the same logic, these texts are not evidence of Sabbath observance by Paul or other Christians.
A Christian service is NOT a non-Christian service attended by Christians. Just like a Catholic Mass is NOT an Adventist Mass when it’s attended by Adventists. Adventists would never call the Mass an Adventist service if their pastor merely attended, but they don’t want to same logic extended to the Bible.
Next we must ask, what was Jesus doing by attending the synagogue on the Sabbath, and what was Paul doing ? First, Jesus – remember that there isn’t a biblical command to gather together on the Sabbath (as far as I am aware) – the command is to REST on the Sabbath, to keep it HOLY. Synagogue attendance was not compulsory as part of a Sabbath obligation like attendance at Mass is for Catholics on Sundays. The reason Jesus went to the synagogue was therefore NOT as part of his Sabbath duty, but rather because this was a convenient time to find all the Jews gathered together. Generally, although not as part of their duty to obey the Sabbath commandment, Jews gathered together in the synagogue to do Bible (Old Testament) study and hear the preaching of the wiser men, like the priests. Jesus was included in this group, as is seen in the text of the Bible, where he gets up to read from the Bible (Isaiah) and gives a brief comment on it afterwards. So attendance at the synagogue cannot be seen as obedience to the Sabbath commandment – it was merely taking the right opportunity because the Jews were all in one place on this day. YES – Jesus DID obey the Sabbath commandment, but this is because he was still under the old law of Moses, which included the ceremonial weekly Sabbath day observance. He kept the law perfectly.
What was Paul’s intent by attending the synagogue on the Sabbath ? As we can discover from looking at Judaism from around that time, attendance at the synagogue was not a part of the Sabbath day obligation to rest and keep the day holy. It was merely a good opportunity for the studying of God’s word, and for hearing wise sermons. By attending the synagogue Paul was not fulfilling ANY Sabbath day obligation to rest or keep the day holy. In fact, the Bible reveals what the purpose of his visits were – to preach. This was the perfect opportunity to preach to the yet unbelieving Jews about Jesus, and since it was a time when general wisdom was shared and discussed, many unbelieving Gentiles were in attendance too. Many Christians of both Jewish and Gentile origin ALSO attended, no doubt, to a) spread the Gospel message, b) hear the wisdom preached by Paul and the other Apostles. So Paul could not have been fulfilling any Sabbath obligation by attending services on Saturday – it is revealed in the Bible that his purpose was to preach. There was no better time to do this – on Sunday through Friday the Jews would be doing their own thing, and Paul could not preach to them as a group. On these days, as one passage I think in Acts reminds us, he would often attend general public meetings led by philosophers of other religions. No-one claims that attendance at a Gentile religious discussion on a week day was an observance of this particular week day, and therefore if Paul and the Apostles preached to unbelievers EVERY day of the week, we cannot claim that because they ALSO did it on Saturday, we must observe Saturday as holy.
We need to find in the Bible a specific day of the week which Christians kept holy, on which Christians held PRIVATE worship services for Christians only (Paul tells us that only Christians were allowed to partake of the Lord’s Supper.) We find NOT ONE text that tells us Christians observed Saturday. Yet we find several texts that tell us that Christians DO NOT HAVE TO observe Saturday – Gal 4:10-11, Col 2:16, Rom 14:5-6. Col 2:16 uses a term that ALWAYS refers to the weekly Sabbath wherever else it is used in the Bible, and tells us that the weekly Sabbath (as well as the other festivals like Passover) are mere shadows of Christ. If we do not have to keep the shadow Passover, why must we keep the shadow Sabbath ? After all, God revealed both of these days directly through Moses.