Q: Can sources other than the Torah serve a Noahide as the basis for his life?
What makes a religion not a Noahide movement?
-- Questions by Mattitjahu; replies by Rabbi Oury Sherki in bold type.
When somebody is a Noahide by logic and intellect and therefore accepts the seven mitzvot, then:
1. Is it true that other sources can be his source for his way of life, for example, the Koran, New Testament, Veda, etc? That is, Torah is certainly the highest source of knowledge, but a Noahide who is not aware of this might choose to live based on other sources.
Is this true? Not in an absolute sense. According to Rabeinu Bachayei on Devarim 31:16 it is tolerated for the nations during a time when they do not have any access to higher level spirituality (but the Rambam probably doesn't agree). Poskim are divided on this point too. I think that it will be one of the cardinal questions to be studied by rabbis in the coming years.
2. If the above proposal is indeed true, doesn't that imply that almost all religions are Noahide 'movements'? They have a tendency towards the Noahide principles but they are not completely part of the movement.
3. What makes a religion not a Noahide movement? Not accepting the seven laws and their Mosaic origin.
4. When one can be a Noahide without Torah, why should he support the Jews (in political terms)? Because the Jewish people are the guarantee of the authenticity of faith, values and worship, and the source of divine revelation.
5. How can we be sure that a Noahide will not misuse the Torah? (After all, he is not a ger toshav.) We cannot be absolutely sure.