"... If I may interject a thought?:
Acts 7:38 KJB - This is he, that was in the church in the wilderness with the angel which spake to him in the mount Sina, and with our fathers: who received the lively oracles to give unto us:
That is a NT text, referring to past events. However, notice, that Luke under inspiration of the Holy Ghost, refers to the body of people with Moses as "the church in the wilderness".
Are they not our brothers and sisters in Christ Jesus? Are they not members of that one great body from Adam [redeemed] unto the last repentant member?
Does the body then have differing gathering time than we do today? How shall we be one in the New Heavens and New Earth?
Isaiah 66:23 KJB - And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the LORD.
Notice, that the "church in the wilderness" of the past has command to gather on the 7th day the sabbath of the LORD their God:
Leviticus 23:3 KJB - Six days shall work be done: but the seventh day is the sabbath of rest, an holy convocation; ye shall do no work therein: it is the sabbath of the LORD in all your dwellings.
We, today, are part of that "church", they being of Israel then, and we being of Israel today - all of us together as one body, which shall be seen together in the translation and resurrection. As they, so likewise we:
Exodus 20:6 KJB - And shewing mercy unto thousands of them that love me, and keep my commandments.
John 14:15 KJB - If ye love me, keep my commandments.
Both Jews and Gentiles repenting unto God, understood these things:
Exodus 20:11 KJB - For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
Jews:
Acts 4:24 KJB - And when they heard that, they lifted up their voice to God with one accord, and said, Lord, thou art God, which hast made heaven, and earth, and the sea, and all that in them is:
Gentiles:
Acts 14:15 KJB - And saying, Sirs, why do ye these things? We also are men of like passions with you, and preach unto you that ye should turn from these vanities unto the living God, which made heaven, and earth, and the sea, and all things that are therein:
Acts 14:16 KJB - Who in times past suffered all nations to walk in their own ways.
Notice the gathering together:
Acts 13:42 KJB - And when the Jews were gone out of the synagogue,
the Gentiles besought that these words might be preached to them the next sabbath.
Acts 13:43 KJB - Now when the congregation was broken up, many of the Jews and religious proselytes followed Paul and Barnabas: who, speaking to them, persuaded them
to continue in the grace of God.
Acts 13:44 KJB - And
the next sabbath day came almost the whole city together to hear the word of God. ..." -
GOD'S WORD vs TRADITIONS OF MEN; Sabbath vs Sunday