His father, who bore the same name with himself, had originally belonged to an obscure sect called Hypsistarians or Hypsistians, of whom we know little except what we learn from Gregory of Nazianzus and his namesake of Nyssa.  They seem to have held a sort of syncretist doctrine, containing elements derived from heathen, Christian, and Jewish sources.  They were very strict monotheists, rejecting both polytheism and the doctrine of the Trinity, and worshipping the One Supreme Being under the names of The Most High and The Almighty, and the emblems of Fire and Light, but with no external cultus; for they rejected sacrifice and every outward form of worship, holding adoration to be an exclusively interior and spiritual act.  With singular inconsistency, however, they adopted the observance of the Jewish Sabbath, and the Levitical prohibition of certain kinds of food.  They were but few in number, and their influence was insignificant even in Cappadocia, which was the headquarters of sect. ἐκ δύοιν ἐναντιωτάτοιν συγκεκραμένης, ἑλληνικῆς τε καὶ νομικῆς τερατείας· ὧν αμφοτέρων τὰ μέρη φυγὼν, ἐκ μέρων συνετέθη.  Τῆς μέν γὰρ τὰ εἴδωλα καὶ τὰς θυσίας ἀποπεμπόμενοι, τιμῶσι τὸ πῦρ καὶ τὰ λυχνα· τῆς δὲ τὸ σάββατον αἰδούμενοι καὶ τὰ περὶ τὰ βρώματά ἐστιν ἃ μικρολογίαν, τὴν περιτομὴν ἀτιμάζουσιν.—Or. xviii. 5.  From this form of error the elder Gregory was converted by the influence of his wife, Nonna; and soon after his conversion was consecrated to the bishopric of Nazianzus.