The New International Standard Bible Encyclopaedia says, "No difficulties were put in the way of those strangers who wished to settle down in the land of Israel. All strangers, the third generation of Egyptians and Edomites included, and only Ammoniites and Moabites excluded could enter “the congregation of God” without circumcision and without the obligation to keep the ceremonial law. *The stranger within the gate was free to eat meat which was prohibited to the Israelite (Dt. 14:21). If, however, the stranger wished to take part in the Passover, a feast that permeated with the national ideals, he must be circumcised. The keeping of the Sabbath and other feasts was regarded rather as a privilege than as a duty (Ex 23:12, Dt. 16:11, 14) but acording to Lev. 16:29 he was obliged to fast on the Day of Atonement." *
The NISBE cites Exodux 23:12 as a reference for the notion that the keeping of the Sabbath by Gentiles was a privelege and not a duty:
*For six days you may do your work, but on the seventh day you must rest, that your ox and your *** may also have rest, and that the son of your maidservant and the alien may be refreshed. *
Nowhere is it mentioned that the Gentile living amongst the Israelites was to adhere to the law, or teaching, commanding Israelites to keep the Sabbath. On the contrary, uncircumcised Gentiles were known as “God-fearers” as compared to “proselytes,” or those who were circumcised. The moment God-fearers became proselytes, by being circumcised, they were commanded by the Law of Moses to observe all the laws, including the law pertaining to the observance of the Sabbath. However, since many Gentiles could not pragmatically observe the Sabbath, many remained God-fearers. Our Lord speaks of this to the Pharisees when he says,
“Woe to you, scribes and Pharisees, you hypocrites. You traverse sea and land to make one convert, and when that happens you make him a child of Gehenna twice as much as yourselves.”
The NAB Commentary confirms the notion that any Gentile who converted to the Judaism by circumcision was bound to keep the requirements of the Law. We hear Paul speaking many times throughout his epistles about how adherence to the Law is certain death - for who can perform it?
As Christians, we follow the Ten Commandments, an abbreviated form of the Law. As Christians, we are also urged to follow the Noachide Laws - the laws given by God to Noah, incumbent upon all of mankind to accept and practice. In Jewish theology, the Ten Commandments were designated for the Children of Israel alone: Gentiles are not obligated to adhere to these laws in any fashion, but Gentiles are obligated to keep the Noachide Laws. These Laws are:
#1 - You shall practice equity, establish and promote justice.
#2 - You shall not commit idolatry.
#3 - You shall not commit blasphemy.
#4 - You shall not commit sexual immorality.
#5 - You shall not commit murder.
#6 - You shall not commit theft.
#7 - You shall not eat the limb torn from a live animal.
Many of these laws are echoed in the Ten Commandments, except for #7. Similarly, the commandment to observe the Sabbath is not reflected here in the Noachide Laws, the laws incumbent upon all mankind to observe.
Why then ought we to observe the Sabbath since God has not commanded the uncircumcised to do such?