"God Is One" or "the One Is God" in Hellenistic Jewish and Greco-Roman Theology

"God is one" is the theological foundation of many of the world's religions. The Greek version of this expression, heis theos, was especially significant to ancient religious development. Past scholarship has tended to place its emergence early, among the sixth century BCE Presocratic philosophers. In this article, I argue that the expression "God is one" in Greek likely develops later, in Jewish writings of the Hellenistic period. My work supports a minority opinion in the scholarship that attributions in second century Christian apologetics of this expression to Presocratics such as Xenophanes should not be relied upon. Rather, I suggest that the expression heis theos emerged in the context of second to first century BCE Alexandrian Jewish theology in conversation with ideas from Greek philosophy.