Gregory of Nazianzus
The name "Hypsistarioi" first occurs in Gregory of Nazianzus (Orat., xviii, 5) and the name "Hypsistianoi" in Gregory of Nyssa (Contra Eunom., II), about 374 CE. Gregory of Nazianzus describes a syncretic Jewish-pagan group that does not worship idols, reveres lamps and fire, and worships the Almighty ("Pantokrator"). They keep Sabbath and adhere to dietary restrictions, but they do not circumcise. Gregory of Nyssa adds that they refer to God as the Highest ("Hypsistos") or Almighty ("Pantokrator"). Gregory of Nazianzus' description of this cult occurs in his eulogy for his father, who was a Hypsistarian before his conversion to Christianity. This cult may have formed as the native Cappadocian cult of Zeus Sabazios integrated with the cult of Jahve Sabaoth practiced by the numerous and intellectually predominant Jewish colonies, and that associations ("sodalicia, thiasoi") of strict monotheists formed, who fraternized with the Jews, but who considered themselves free from the Law of Moses.