I would suggest that you might want to take a look at three lessons I did on the fourth commandment.
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Years ago, Dr. Bruce Waltke (formerly a Hebrew professor at Dallas Seminary -- now teaching elsewhere) said something like this: "When we come to the New Testament, we must determine whether the New Testament ratifies, modifies, or abrogates the Old Testament law." There are some of the commandments that are clearly carried directly over into the New Testament.
There are things in the law that have been set aside, however. For example, Mark 7:17-23, along with Acts 10 and 11 make it abundantly clear that the clean/unclean food laws of the Old Testament have been set aside -- nullified. These are no longer requirements for the New Testament believer, although freedom is given about doing so (Romans 14:1-10f.), so long as one does not deny the gospel by his practice (see Galatians 2:11-14f.).
The Sabbath was the sign of the Old Covenant (as circumcision was the sign of the Abrahamic Covenant and the rainbow was the sign of the Noahic Covenant), and thus strict Sabbath-keeping does not have the same meaning for those who are now under the New Covenant.
The principle of observing a day of rest, and of freedom from distraction, so that one can devote himself to worshipping God is clearly laid out in the Book of Isaiah:
13 You must observe the Sabbath rather than doing anything you want on my holy day. You must look forward to the Sabbath and treat the Lord's holy day with respect. You must treat it with respect by refraining from your normal activities, and by refraining from your selfish pursuits and from making business deals. 14 Then you will find joy in your relationship to the Lord, and I will give you great prosperity, and cause crops to grow on the land I gave to your ancestor Jacob." Know for certain that the Lord has spoken (Isaiah 58:13-14).
It is good to set a day aside, free from the usual cares and distractions of life, so that one can devote himself to worshipping God. But this day is not specified as -- nor restricted to -- "the Sabbath" in the New Testament, either in Acts or in the Epistles.
The Bible seems to make it clear that observing a Jewish Sabbath is not required:
16 Therefore do not let anyone judge you with respect to food or drink, or in the matter of a feast, new moon, or Sabbath days 17 that are only the shadow of the things to come, but the reality is Christ (Colossians 2:16-17).
5 One person regards one day holier than other days, and another regards them all alike. Each must be fully convinced in his own mind. 6 The one who observes the day, does it for the Lord. The one who eats, eats for the Lord, because he gives thanks to God, and the one who abstains from eating, abstains for the Lord, and he gives thanks to God (Romans 14:5-6).Thus, when we see the church meeting on the first day of the week, rather than keeping the traditional Sabbath (see Acts 20:7; 1 Corinthians 16:2), it should come as no surprise.
I should probably point out that circumcision was required of believers in the Old Testament (Genesis 17:9-14; Leviticus 12:1-3; Joshua 5:1-5). Moses was nearly put to death for neglecting to circumcise his son (Exodus 4:24-26). But circumcision was not required for those who came to faith in Jesus in the New Testament. New believers were baptized, not circumcised. Indeed, Paul both refused and forbade circumcision when it symbolized a person placing themselves under law (Galatians 2:1-10; 5:1-6f.). (I should add that he did have Timothy circumcised, so that being uncircumcised would not hinder the gospel -- Acts 16:3. In this case, Judaisers were not demanding circumcision.).
Once again let me emphasize that setting aside a day of rest, and freedom from distraction, so that one can worship the Lord is a good thing. Where we differ is that this day needs to be the Sabbath Day of the Old Testament.
I hope this answers your questions honestly, directly, and biblically.