God-fearer
God-fearers (Koinē Greek: φοβούμενοι τὸν Θεόν, phoboumenoi ton Theon) or God-worshippers (Koinē Greek: θεοσεβεῖς, Theosebeis) were a numerous class of Gentile sympathizers to Hellenistic Judaism that existed in the Greco-Roman world, which observed certain Jewish religious rites and traditions without becoming full converts to Judaism. The concept has precedents in the proselytes of the Hebrew Bible.
Many of these Greco-Roman sympathizers to Hellenistic Judaism were worshippers of Caelus (the Roman name/equivalent to Yahweh). More generally, God-fearing has come to mean someone who is honestly religious.