We are not saved by keeping any law, because we all have sinned . We are saved by the blood of Jesus through faith. Those with faith live differently than those who don’t, they are a peculiar people who keep God’s commandments and have the faith of Jesus. Rev 14:12
Jesus kept the Sabbath going to the synagogues which we call CHurch because He wants us to be in one body. If we are sick, not a sin to stay home but we can still keep the Sabbath day holy.
God said:
Exo 20:8 “Remember the Sabbath day, to keep it holy. 9 Six days you shall labor and do all your work, 10 but
the seventh day is the Sabbath of the Lord your God.
In it you shall do no work: you, nor your son, nor your daughter, nor your male servant, nor your female servant, nor your cattle, nor your stranger who
is within your gates.
Lev 23:3 ‘Six days shall work be done,
but the seventh day is a Sabbath of solemn rest, a holy convocation. You shall do no work
on it; it
is the Sabbath of the Lord in all your dwellings.
A holy convocation is a holy gathering like in Chruch
Did this change in the New Testament?
Not by Jesus
Luke 4:16 So 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. 17 And He was handed the book of the prophet Isaiah.
Did it change after the Cross?
Acts 13:42 So when the Jews went out of the synagogue, the Gentiles begged that these words might be preached to them the next Sabbath.
Acts 13:44 On the next Sabbath almost the whole city came together to hear the word of God.
Acts 15:21 21 For Moses has had throughout many generations those who preach him in every city, being read in the synagogues every Sabbath.”
Acts 18:4 And he reasoned in the synagogue every Sabbath, and persuaded both Jews and Greeks.
Not by the apostle's
Does it change in the New Heaven and New Earth
Yes. Only because now instead of worshipping Christ in spirit, the saints will be in His physical presence, like at Creation Gen 2:1-3 Gen 1:26 but the Sabbath remains just as what was promised.
Isa 66:23 “For as the new heavens and the new earth
Which I will make shall remain before Me,” says the Lord,
“So shall your descendants and your name remain.
23 And it shall come to pass
That from one New Moon to another,
And from one Sabbath to another,
All flesh shall come
to worship before Me,” says the Lord.
The Sabbath was part of Creation Exo 20:11 Gen 1:23 before sin entered, made for mankind Mark 2:27 to bless and sanctify man Isa 56:1-6 Eze 20:12 because man cannot sanctify themselves, we need God. The Sabbath is a memorial to Creation and our Creator Exo 20:11 why we should not forget what God said to Remember.