Mark 2:28 So the Son of Man is Lord even of the Sabbath. Jesus declares His affiliation with the Sabbath. Luke 4:16 And He came to Nazareth where He had been brought up. And as His custom was, He went into the synagogue on the Sabbath day and stood up to read. Jesus kept the Sabbath! Acts 17:2 And Paul, as his manner was, went in unto them, and three Sabbath days reasoned with them out of the scriptures. This is three consecutive weeks on the Sabbath for those taking note. Matthew 24:20 "But pray ye that your flight be not in the winter, neither on the Sabbath day". This is an event that took place years after the crucifixion. Sounds like it is still valid to me. The Law that God wrote Himself (Ex. 24:12) and spoke Himself (Deut. 4:12,13). You can't go wrong by following Gods own Words, speech or example while on earth. There is NO excuse in the day of judgment. REMEMBER the Sabbath day. The only one with remember in it.
All of which utterly fail to produce any command ever given under the New Covenant to the church to keep the 7th day Sabbath. The Lord also enjoined general obedience to the Scribes and Pharisees, (Mt. 23:2) and kept OT feasts, none of which is binding under the New Covenant, which is distinctively declared to be “Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt.." (Jer. 31:32),
Thus akin to Catholics who assume NT Christians did what is nowhere recorded, you assert that the Holy Spirit would fail to record even one example of a NT church (as a church) specifically keeping the 7th day, despite this being such an important practice, while only showing them specifically meeting on the first day, and treating the sabbath as part of the ceremonial law which Christians are not bound to keep. Based upon your failure to rightly divide the word of Truth you and your elitist cult might as well argue that Christians must be circumcised and keep the feasts to be saved.
The Sabbath was never part of the ceremonial law. There were additional sabbaths that were but the 7th day Sabbath commemorating Creation was never part of that. The 7th day Sabbath is part of the TEN (count them) COMMANDMENTS (not suggestions).
Where is the LAW stating the first day of the week must be kept holy?