God-fearer
A God-fearer or Godfearer was a member of a class of non-Jewish (gentile) sympathizers to Second Temple Judaism mentioned in the Christian New Testament and other contemporary sources such as synagogue inscriptions in diaspora Hellenistic Judaism. The concept has precedents in the proselytes of the Hebrew Bible.
Hebrew Bible
In the Hebrew Bible, there is some recognition of non-Jewish monotheistic worship as being directed toward the same God. This forms the category of yirei Hashem ("יראי השם," meaning "Fearers of the Name", "the Name" being a Jewish euphemism for the Tetragrammaton, cf. Psalm 115:11). This was developed by later rabbinic literature into the concept of Noahides, Gentiles following the seven laws, which rabbinic writings assigned to the Noahic covenant.
Original Greek terms
There are various Greek forms of this term:
the adjective theosebes
the adjective theophobes (Greek θεοφοβείς)
the phrase "fearers of God" (φοβουμενοι τον θεον)
The word may also be related to terms in other languages such as Neo-Persian Tarsàkàn