Many who have found their way to Torah will immediately cling to the false teaching that “Sunday worship” is pagan, and “the church is wrong by having Sunday worship sessions.” They will try to tell you, “Saturday is God’s day of worship; Sunday is not!” Well … that’s not exactly true.
You see, Saturday is YHWH’s Day of REST, not just “worship”; it’s His “weekly date” with us. According to Scripture, we’re supposed to REST on Shabbat (which, on our Gregorian calendars happens to fall on Saturday). And, yes, we are also to worship – but, really, aren’t we supposed to worship Him EVERY day and all the time? (Romans 12:1–2).
Exodus 20:8 "Remember the day, Shabbat, to set it apart for God. 9 You have six days to labor and do all your work, 10 but the seventh day is a Shabbat for ADONAI your God. On it, you are not to do any kind of work -not you, your son or your daughter, not your male or female slave, not your livestock, and not the foreigner staying with you inside the gates to your property. 11 For in six days, ADONAI made heaven and earth, the sea and everything in them; but on the seventh day he rested. This is why ADONAI blessed the day, Shabbat, and separated it for himself. (CJB)
Exodus 31:16 The people of Isra'el are to keep the Shabbat, to observe Shabbat through all their generations as a perpetual covenant. 17 It is a sign between me and the people of Isra'el forever; for in six days ADONAI made heaven and earth, but on the seventh day he stopped working and rested.'" (CJB)
Ezekiel 20: 11 I gave them my laws and showed them my rulings; if a person obeys them, he will have life through them. 12 I gave them my shabbats as a sign between me and them, so that they would know that I, ADONAI, am the one who makes them holy. (CJB)
If you want to accuse Christians of something, then accuse them of not RESTING on the Sabbath, and of committing commerce on the Sabbath, which is also forbidden (see Nehemiah 10:28-39). But don’t ever tell them they shouldn’t “worship” on Sunday or any other day…
And for those who attempt to suggest that this Old Testament Jewish stuff doesn’t apply to them because Jesus somehow abolished it, here’s a little history:
No matter who instituted Sunday worship, in Yeshua's time, both Jews and Gentiles alike, regularly attended the synagogue for worship on the seventh day - which, on our Gregorian calendars falls on Saturday), and the fact that interested Gentiles in Antioch requested further instruction of Paul "on the next Sabbath" is irrefutable evidence that no separate Sunday (1st day) meetings were being held there by those early Christians.
The Gentiles were willing to wait an entire week, till the next Saturday, for a meeting because they knew that Paul and his companions did not normally meet for worship on a Sunday. Acts 13:42-44 tells us that, on the next Sabbath (Saturday) almost the whole city arrived for the meeting.
And by the way, some insist that Acts 20:7 reveals “Sunday worship,” but this is not true. Fact is, Jewish believers in Yeshua continued meeting at synagogue (or the Temple) for Sabbath. Common practice would be havdallah - meeting in homes after sundown on Saturday to continue discussions and praise from the Sabbath, which explains Paul "preaching until midnight" in Acts 20:7. The first day of the week for Jews (like Paul) began at sundown at the end of the Sabbath - Saturday evening - not "Sunday."
Furthermore, the SEVENTH DAY Sabbath is a HOLY day! Fact is, neither the Father nor the Son has ever claimed the first day as His own in any higher sense than He has each or any of the other laboring days. Neither of them has ever placed any blessing upon it, or attached any sanctity to it. The Bible tells us God expressly reserved the seventh day to Himself, placing His blessing upon it, and claimed it as His holy day. (Genesis 2:1-3.) Moses told Israel in the wilderness of Sin of the sixth day of the week, "Tomorrow is the rest of the holy Sabbath unto the Lord." (Exodus 16:23)
BOTTOM LINE: There’s not a thing wrong with “worshiping” on Sunday. Christians need to learn that when YHWH says to REST on HIS Sabbath, He means REST! Cease from doing your weekly “stuff”; your income-producing work and anything else that your mind and body needs REST from.
These rules were never meant to be “just for the Jews.” Since we are “one in Messiah” (Galatians 3:28 and Numbers 15:13-16) we are to do exactly as HIS people do! And HIS people (which includes YOU) REST on His WEEKLY and YEARLY Shabbats….