Christians are commanded to keep the seventh-day Sabbath (aka Saturday) holy and rest on that day for many reasons:
1. Yahweh God Almighty made it holy and he himself rests on it at creation and every week thereafter.
2. The first man Adam and the generations after him rest on the seventh-day to this very day.
3. God commanded man to allow his livestock to rest on the seventh-day to keep in harmony with God's natural timing.
4. Every seventh-day shabbath reminds the world every week that Yahweh created the heavens and earth in seven days.
5. Substituting another day of the week in place of the seventh-day destroys the message of God's creation of heaven and earth.
6. Yahusho (Jesus) the Messiah, his Israeli disciples and the gentile congregations kept and rested on the seventh-day.
7. Our Saviour of Mankind (Jesus) said: “Don’t think that I came to destroy the law or the prophets. I didn’t come to destroy, but to fulfill. For most certainly, I tell you, until heaven and earth pass away, not even one smallest letter[e] or one tiny pen stroke[f] shall in any way pass away from the law, until all things are accomplished. Whoever, therefore, shall break one of these least commandments, and teach others to do so, shall be called least in the Kingdom of [Yahweh]; but whoever shall do and teach them shall be called great in the Kingdom of [Yahweh]. For I tell you that unless your righteousness exceeds that of the scribes and Pharisees, there is no way you will enter into the Kingdom of [Yahweh]. (Matthew 5:17-20)
Really: Many Israeli's and gentiles of Yahusho's day thought that he came to DESTROY the ten commandments; by telling them not to obey them. And after he died and rose from the dead, heaven and earth still did not pass away. Why not? Simple. Because ALL things have NOT been accomplished. Some people thinks that his resurrection accomplished the "ALL" things spoken here. Jesus did not go into detail as to what is this "ALL THINGS" that was to be accomplished. But apparently it's accomplishment would signify the passing away of heaven and earth. And his twelve disciples and the early congregations in the first two centuries did not destroy the law and the prophets. They in fact kept the ten commandments especially the fourth commandment by resting weekly on the seventh-day sabbath and keeping it holy.
But this is simply my observation and opinion on the subject; because I have not always kept the seventh-day sabbath in my early years.