The Sabbath is one of the bone of contention among Christians. Sabbath was a an everlasting covenant of God to Israel and should be handed down from generation to generation. It's a day of the Lord, wherein Israel people should gather together to praise, glorify and talk about God. If Sunday is the first day of the week, then this should be Saturday. God said , that He worked for 6 days, and on the 7th day , He rest. God wanted us to do the same. We work for 6 days and the 7th should be a day of rest and should be given as the day of the Lord. However, during the reign of Constantinople, when Christianity was declared as the national religion, they changed the Sabbath from Saturday to Sunday. Since Romans were pagans, they changed the Saturday to Sunday to still incorporate their worship to their Sun god which they do during Sunday. That's actually the origin of the day Sunday, in honor of their Sun god. Among Christian church today, Sunday is the day of the Lord which is called Sunday Worship. Actually Sunday Worship today is aligned with today's contemporary world wherein Sunday is the rest day of all working people. However, still according to God's word, Sabbath should still fall on Saturday. However, We know that God is an omniscient or an all knowing God who knows everything of the future. Remember that God's word is always applicable ito all generation. As long as you will give one dedicated day for Him, you are still following and being obedient to His command.Although He gives this to the Israel people,since Jesus ,Son of Man is Lord of the Sabbath, who was resurrected on Sunday morning, Christians follow this day as the day of the Lord.