Genesis 2:3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
This was written "before" there were Jews. It was only Adam and Eve.
Exodus 20:10 But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates
Stranger means Gentile (according to Strongs)
It does't say the sabbath of the Jews, it says the sabbath of the Lord.
But the New Testament doesn't tell us to keep the sabbath. Oh ?In the New Testament we see the people- not just the Jews- celebrating the sabbath!
Mark 2:7 And he said unto them, The sabbath was made for man, and not man for the sabbath
definition of man- a human being, whether male or female (according to Strongs) doesn't say Jewish man, says humans.
Acts 13:42 And when the Jews were gone out of the synagogue, the Gentiles besought that these words might be preached to them the next sabbath.
The saved by grace Gentiles were celebrating the sabbath.
Remember the Ten Commandments contain the admonition to keep the sabbath. If you negate that commandment then you need to negate the other commandments.
We will all be celebrating the sabbath on the new earth -Isaiah 66:22- so why would we not do it now? Will we suddenly turn into Jews?
These are the reasons I believe sabbath is for today, for all people and not jut Jews. These are the reasons I celebrate sabbath.