we have this:
Question: "What day is the Sabbath, Saturday or Sunday? Do Christians have to observe the Sabbath day?"
Answer: It is often claimed that "God instituted the Sabbath in Eden" because of the connection between the Sabbath and creation in Exodus 20:11. Although God's rest on the seventh day (Genesis 2:3) did foreshadow a future Sabbath law, there is no biblical record of the Sabbath before the children of Israel left the land of Egypt. Nowhere in Scripture is there any hint that Sabbath-keeping was practiced from Adam to Moses.
The Word of God makes it quite clear that Sabbath observance was a special sign between God and Israel: "And Moses went up to God, and the Lord called to him from the mountain, saying, "Thus you shall say to the house of Jacob, and tell the children of Israel: 'You have seen what I did to the Egyptians, and how I bore you on eagles' wings and brought you to Myself. Now therefore, if you will indeed obey My voice and keep My covenant, then you shall be a special treasure to Me above all people; for all the earth is Mine'" (Exodus 19:3–5).
“Therefore the children of Israel shall keep the Sabbath, to observe the Sabbath throughout their generations as a perpetual covenant. It is a sign between Me and the children of Israel forever; for in six days the Lord made the heavens and the earth, and on the seventh day He rested and was refreshed” (Exodus 31:16–17).
In Deuteronomy 5, Moses restates the ten commandments to the next generation of Israelites. Here, after commanding Sabbath observance in verses 12–14, Moses gives the reason the Sabbath was given to the nation Israel: "And remember that you were a slave in the land of Egypt, and the Lord your God brought you out from there by a mighty hand and by an outstretched arm; therefore the Lord your God commanded you to keep the Sabbath day" (Deuteronomy 5:15).
Notice the word therefore. God's intent for giving the Sabbath to Israel was not that they would remember creation, but that they would remember their Egyptian slavery and the Lord's deliverance. Note the requirements for Sabbath-keeping: A person placed under that Sabbath law could not leave his home on the Sabbath (Exodus 16:29), he could not build a fire (Exodus 35:3), and he could not cause anyone else to work (Deuteronomy 5:14). A person breaking the Sabbath law was to be put to death (Exodus 31:15; Numbers 15:32–35).
An examination of New Testament passages shows us four important points: 1) Whenever Christ appears in His resurrected form and the day is mentioned, it is always the first day of the week (Matthew 28:1, 9, 10; Mark 16:9; Luke 24:1, 13, 15; John 20:19, 26). 2) The only time the Sabbath is mentioned from Acts through Revelation it is for evangelistic purposes to the Jews and the setting is usually in a synagogue (Acts chapters 13–18). Paul wrote, "to the Jews I became as a Jew, that I might win Jews" (1 Corinthians 9:20). Paul did not go to the synagogue to fellowship with and edify the saints, but to convict and save the lost. 3) Once Paul states "from now on I will go to the Gentiles" (Acts 18:6), the Sabbath is never again mentioned. And 4) instead of suggesting adherence to the Sabbath day, the remainder of the New Testament implies the opposite (including the one exception to point 3 above, found in Colossians 2:16).
Looking more closely at point 4 above will reveal that there is no obligation for the New Testament believer to keep the Sabbath, and will also show that the idea of a Sunday "Christian Sabbath" is also unscriptural. As discussed above, there is one time the Sabbath is mentioned after Paul began to focus on the Gentiles, "So let no one judge you in food or in drink, or regarding a festival or a new moon or Sabbaths, which are a shadow of things to come, but the substance is of Christ" (Colossians 2:16–17). The Jewish Sabbath was abolished at the cross where Christ "wiped out the handwriting of requirements that was against us" (Colossians 2:14).
This idea is repeated more than once in the New Testament: "One person esteems one day above another; another esteems every day alike. Let each be fully convinced in his own mind. He who observes the day, observes it to the Lord; and he who does not observe the day, to the Lord he does not observe it" (Romans 14:5–6a). "But now after you have known God, or rather are known by God, how is it that you turn again to the weak and beggarly elements, to which you desire again to be in bondage? You observe days and months and seasons and years" (Galatians 4:9–10).
But some claim that a mandate by Constantine in A.D. 321 "changed" the Sabbath from Saturday to Sunday. On what day did the early church meet for worship? Scripture never mentions any Sabbath (Saturday) gatherings by believers for fellowship or worship. However, there are clear passages that mention the first day of the week. For instance, Acts 20:7 states that "on the first day of the week the disciples came together to break bread." In 1 Corinthians 16:2 Paul urges the Corinthian believers "on the first day of the week let each one of you lay something aside, storing up as he may prosper." Since Paul designates this offering as "service" in 2 Corinthians 9:12, this collection must have been linked with the Sunday worship service of the Christian assembly. Historically Sunday, not Saturday, was the normal meeting day for Christians in the church, and its practice dates back to the first century.
The Sabbath was given to Israel, not the church. The Sabbath is still Saturday, not Sunday, and has never been changed. But the Sabbath is part of the Old Testament Law, and Christians are free from the bondage of the Law (Galatians 4:1-26; Romans 6:14). Sabbath keeping is not required of the Christian—be it Saturday or Sunday. The first day of the week, Sunday, the Lord's Day (Revelation 1:10) celebrates the New Creation, with Christ as our resurrected Head. We are not obligated to follow the Mosaic Sabbath—resting, but are now free to follow the risen Christ—serving. The Apostle Paul said that each individual Christian should decide whether to observe a Sabbath rest, “One man considers one day more sacred than another; another man considers every day alike. Each one should be fully convinced in his own mind” (Romans 14:5). We are to worship God every day, not just on Saturday or Sunday.