The word, sabbath, only means rest or cease. There were many sabbaths all throughout the OT. The rest is not what makes a day holy, the day is holy so we rest to acknowlege its holiness. With this, we have to determine why a day is holy. The seventh day of creation is holy because it's a sign of creation and testifies of a Creator. It's used for many other signs as well such as a sign to Israel to remind them of a time in slavery when they did not have freedom to cease labor to worship God. It's used as a means to testify which God we worship. It's used to setarate a people for God. It's used as a sign of delieverence from the bondage of sin. It's also used as a picture of our heavenly kingdom time when we, as God's people, will all be together in the kingdom of God. Some the signs that the Sabbath is used for are not for us but some are. Either way, the day is holy and protected by Law because it was created holy and remains holy. It's holiness has nothing to do with sin, in the same way, marriage is holy.
I choose to keep both marriage and the seventh day, just as God says and Jesus taught.