Noahidism

Noahidism has existed since at least the Second Temple era; there are references from the Second Temple era onwards of halachically and communally accepted groups non-Jewish worshipers of HaShem called the Phebomenoi, or Heaven-Fearers: Goyim who adhered to the Noahide laws, who lived and worshiped in tandem with their local Jewish communities- and whom those communities themselves documented among them as being allies who were separate from the general pool of Gentiles.

Unfortunately regular antisemitism, persecution, oppression, and dispersion of Jewish populations ultimately resulted in Noahidism falling by the wayside. Over the course of the centuries it nearly entirely disappeared as a result; with a few individual exceptions, the Noahide movement didn't begin to reappear until largely the 19th and 20th centuries.

Modern Noahidism, like its predecessor, is a Gentile-Centered religious movement founded on the fundamental principle that Gentiles (non-Jews) are not required to convert to Judaism, but are required to follow 'the Seven Laws of Noah', in order to have a place in Olam Ha-Ba alongside the Jewish people. For this reason, the Noahide movement is not, in and of itself, a religion insomuch as it is a set of spiritual laws and guidelines that must be followed in order to live specifically as a "Righteous Gentile" among Jews.

The modern movement is based predominantly within the ideology of modern Orthodox Judaism, and- while it has earlier roots prior to the two great World Wars- solidified in its current form in roughly the late 1980's and early 1990's. As a result of the centuries of loss, and the only recent resurgence, however, many Noahide-specific customs and rituals are still developing; there is much debate surrounding them, where the boundaries are, and their legitimacy, for this reason. Noahides have also been explicitly warned against making Noahidism into any kind of a religion of its own (especially on their own without proper Rabbinical guidance). And it is made explicitly clear that Noahides are not Jews and should not mislead others into believing such.