By some traditions today is the birthday of the prophet Zoroaster.
Zoroaster is often considered the first monotheist (Please note this is a fact challenged with some vigor at my Facebook page by some of a more scholarly turn than I), although as his dates are in fact far from certain some Jews might reasonably object. When the Jewish faith evolved from henotheist (the belief in many gods but yours is best) to monotheist (only one deity worthy of the name) is debated. But we know with certainty Judaism is monotheistic from the Babylonian Captivity in seventh century before the common era, when it appears to have taken its modern contours. At the same time it looks like the mainstream of scholarship is drifting in the direction of the tenth century before Jesus for Zoroaster, which makes him a competitor only with the Pharaoh Akhenaten, who is probably better described as a henotheist than a monotheist…
Once the official religion of various Near and Middle Eastern empires, today a small remnant continues, with guestimates of a quarter of a million to maybe two and a half million adherents, most of whom live in India.
While Zoroaster’s religion held up a single true god, Ahura Mazda, functionally the religion was an ethical dualism with a constant struggle between good and ill. It also upheld moral agency and claimed we have freedom to choose, with consequences in those choices.
Oh, Jews and Christians and therefore Muslims, too, can also thank Zoroastrianism if not Zoroaster directly for angels.
Various other elements of the religion are now found in Judaism, Christianity and Islam along with various Western gnostic streams.
Truthfully I’m not sure whether to thank him for monotheism, which in my view has not been proven to be particularly helpful to the human condition, but, still, it all begins, or seems to, with him, and it is worth noting…