Sabbath is Saturday, not Sunday
Years ago I changed from Sunday worship to Saturday worship because upon being challenged to prove from the Bible that Jesus Christ had changed the Sabbath "day" from the "seventh day" to the first day, I could not prove the change.
I was holding to a tradition that I believe millions of Christians have for centuries without looking to see what the Bible actually said. In seeking to see what the Bible teaches about the Sabbath "day," I learned that it was the Roman Church that changed the Sabbath "day" to the first day of the week. For example, per James Cardinal Gibbons, Archbishop of Baltimore (1877-1921), in a signed letter: '"Is Saturday the seventh day according to the Bible, and the Ten Commandments? I answer, yes. Is Sunday the first day of the week and did the Church change the seventh day -- Saturday -- for Sunday, the first day? I answer, yes. Did Christ change the day? I answer, no. Faithfully yours, J. Card. Gibbons.'"
Another quote by Gibbons per Peter Gelemann, CSSR, A Doctrinal Catechism, 1957 edition, p.50: '"Question: Which is the Sabbath day? 'Answer: Saturday is the Sabbath day. 2) 'Question: Why do we observe Sunday instead of Saturday?" 'Answer: We observe Sunday instead of Saturday because the Catholic Church in the Council of Laodicea, transferred the solemnity from Saturday to Sunday.'" This is from Canon 29, Council of Laodicea 4th century AD.
I found in the law: "...the seventh day is the Sabbath of the LORD thy God" (Exodus 20:10), a specific "day," the "seventh day." Sunday is the first day. I also found that days one through six were work days and the seventh day was "the rest day." God sanctioned the first day a work day.
The church world has negated God's word, (Exodus 20:11) making the no-work Sabbath day a work day and the work-day Sunday a rest day. Exodus 20:11 also teaches that the Sabbath "day" is "hallowed."
Sunday is not hallowed. In the beginning when God rested on the seventh "day," I found that he "blessed the seventh day, and sanctified it" (Genesis 1:3). These protestations about the Sabbath "day" cannot be transferred to Sunday because they pertain to the "seventh day."
Churches claim that Sunday is the Lord's Day and this gives justification to rest and worship on that day. The truth is that Sunday is not the Lord's Day, Saturday is. Jesus said: "Therefore the son of man is Lord also of the Sabbath day." (Mark 2:28; Matt 12:8). Again, in the New Testament, I noticed the Sabbath is a "specific day," Sabbath day, not simply Sabbath.
Sunday, the first day, is the day of the Lord's Resurrection. This does not make it the "Christian Sabbath" as most Christians say. The Old Testament Sabbath "day" and the New Testament Sabbath "day" are the same "seventh day." Thus I learned, Jesus made no changes from Saturday to Sunday because "Jesus Christ is the same yesterday, and today, and forever" (Hebrews 13:8). Therefore, the "Christian Sabbath" is an unbiblical tradition.