One of the most neglected categories, even in “Biblical Theology,” is that of the Old Testament “Righteous Gentile.” The assumption is that the Jews, as special people of God, are coterminous with the saved in the Old World. “Covenant Theology” especially propagates this, as “the Church” is often equated with “Israel.” However, upon closer inspection, we can think of many saved non-Jews. Moses’ father-in-law is one example. Hiram of Tyre is another. Jonah’s audience in Ninevah is another group. We could even include Namaan the Syrian in the list.
Beyond these cursory examples, there is actually a rich tradition within Judaism. The “law of the nations” or the “Noahide order” was a rabbinic expression used to explain the existence of the “God-fearer.” Mark Nanos, in his provocative Romans commentary, explains:
While these gentiles did not keep the Jewish law per se (the 613 commandments of Torah), they kept what was later referred to in rabbinic Judaism as the “Noahide” or “Noachian Commandments.” These Noahide Commandments trace their roots to biblical antecedents, particularly to the Mosaic model for the laws governing the “resident alien” living in Palestine, the “stranger within your gates” (Lev. 16-26; Ex. 12:18-19; 20:10-11). In other words, the Levitical laws provided the historic halakha for governing hte minimal requirements of purity and righteousness for foreigners dwelling in the land of Israel. These rules of behavior evolved during Diaspora Judaism into the seven central religious and ethical principles for the “Sons of Noah,” that is, for describing the behavior of gentiles who were righteous without becoming Jews, and for those gentiles who were in the process of conversion to Judaism. The “righteous gentiles” need not take upon themselves the 613 commandments of Torah that applied to Jews in their worship of the One God, but they must obey at least these seven. These “commandments” were linked to the covenant with Noah along with the rainbow (Gen. 9:1-17, 18ff.), in that they described just and proper behavior for the fathers of Israel (not only Abraham, but all his descendants until Moses received the Law at Sinai), and they became the prevailing criteria for defining the operative features of the faith and practice that would be expected to characterize all the “righteous gentiles” standing outside the covenant with Israel thereafter.
~The Mystery of Romans pg. 51-52
Nanos goes on to propose that these are the “righteous Gentiles” in Romans 2. He believes that this category is fundamental for understanding Paul’s theology, and without agreeing with everything in Nanos, on this point I think he’s right.
Acts 15 does end with a short list of requirements for the Gentiles, after all. The Jerusalem Council does not simply say “faith,” but rather adds a few rules to abide by.
I do think those rules were temporary, and that is where I disagree with Nanos; however the Jew and Gentiles relationship, along with Mosaic sensitivities- as opposed to a complete rupture- is a major component of Paul’s ministry in Acts, as well as his writing about the “weaker brother” in his epistolary literature.