Then he said to them, “The Sabbath was made for man, not man for the Sabbath. So the Son of Man is Lord even of the Sabbath.” Mark 2:27-28
Jesus clearly states that the Sabbath day was created for man (not only for the Jews) and that He is Lord of the Sabbath. Of course, all Christians keep the spiritual Sabbath by default as the gospel teaches us to rest from our works and to glory in the work of God on our behalf. Jesus offers salvation as a gift as we rest in His work on the cross. But there is still a command to reserve this day for physical rest and worship, and there is a blessing that comes only when this is observed.
No one is going to be saved or lost based on their observance to this commandment, but this will be one way to see through the end time deceptions that will be ushered in by the anti-Christ.
The REAL Jesus is Lord of the SABBATH!