God created the world in six days and on the seventh day, he rested.
So, also, we are to rest.
Shabbat, or the Jewish Sabbath, is a day of rest and spiritual enrichment observed from Friday evening to Saturday evening, commemorating God's creation.
The Jewish people teach that the Day of Rest is from Friday sunset to Saturday nightfall.
What is to be THE HOLIEST DAY OF THE WEEK is often "the most sinful" for others who do not keep the Sabbath day.
The 7th Day Adventists teach the Seventh Day of Rest.
No where in the Bible does it command otherwise.
Some religions are right about somethings and wrong about others.
So, I think the 7th Day Adventists got it right in part about the Seventh Day. While other Christian faiths get it wrong about the Day of Rest.
We can't be right on everything.
But from creation of the world to the present day, how can we be sure which day is the seventh day?
People lose count. I often forget which day of the week it is.
God only knows with certainty.
People are often wrong. And on one side of the world, it is daytime and on the other side of the world, it is night time.
God only gets it right.
A dictionary says:
Shabbat (Hebrew: שַׁבָּת) is the Jewish day of rest, celebrated on the seventh day of the week, from just before sunset on Friday until nightfall on Saturday. It is a time for spiritual reflection, family gatherings, and abstaining from work, allowing individuals to focus on rest and worship. The term "Shabbat" derives from the Hebrew root meaning "to cease" or "to rest".
In the Old Testament, one thing punishable by death was working on the Sabbath.
In the New Testament, we are to enter a Sabbath Day of rest.
The disobedient do not enter that rest.
Hebrews 3 and Hebrews 4 speak of entering God's rest.
Worship God any and every day of the week you like. But the Seventh Day of Rest has not changed.
Meet with other Christians any day of the week you like. But the Day of Rest has not changed.
I often think that Christians like to do everything opposite of the Jews.
The Bible speaks of a 7th Day of Rest, but we observe the First Day, Sunday as the Day of Rest. That is like God rested The First Day.
The Jewish People celebrate THE PASSOVER; while Christians celebrate EASTER which is hardly Christian at all by its name.
The Bible says that Jesus is "the sacrificed lamb that was slain." But when remember the event of Jesus death and resurrection, we eat pig on easter. Jesus is not the Sacrificed Ham. Jesus cast demons into pigs. To eat pig is not kosher.
Point being, the Christianity is often the opposite of what is taught in the Bible.
“But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Savior on the same day rose from the dead” (First Apology 67 [A.D. 155]).
The Didascalia
“The apostles further appointed: On the first day of the week let there be service, and the reading of the holy scriptures, and the oblation [sacrifice of the Mass], because on the first day of the week [i.e., Sunday] our Lord rose from the place of the dead, and on the first day of the week he arose upon the world, and on the first day of the week he ascended up to heaven, and on the first day of the week he will appear at last with the angels of heaven” (Didascalia 2 [A.D. 225]).
ML, you say, "10 commandments moral laws are still valid."
But you have been saying that Fourth Commandment to remember the Sabbath day and to keep it HOLY is no longer valid.
So, you have gone from "still valid" to no longer valid, and back and forth, then to and fro. And at the same time you say not to be moved by every wind of doctrine while you surely oppose the Fourth Commandment to remember the Sabbath Day and keep it HOLY.