In Genesis 2:2-3 God rested on the seventh day. A sabbath or shabbat is what we get from Almighty God's rest and His finished work. So He enjoyed all that He created and said it was good (Genesis 1:4,10,12,18,21,25,31) and there is nothing man can add!
Jesus Christ has completed our redemption so really the only thing man can do is to believe on the name of Jesus Christ and enjoy the rest we have in our Father and God. We use this time, the sabbath, in what we call Sunday, to worship and praise our Lord for what He created for mankind from the beginning to today and all He's done for His family. So let's give Him continual praise with thanksgiving as long as we draw breath. Amen and Amen!