This from Dick Harfield on Quora seems a good summary :
" More so than Zoroastrianism, Judaism is an overlapping series of religions, each of which took from its predecessor and added something new. So, before we compare the antiquity of Judaism with that of Zoroastrianism, we have first to answer which ‘Judaism’ we mean.
- The Israelites and the Jews of the early monarchic period were polytheistic and continued to worship the gods of their Canaanite forebears, with the addition of a new patron God, Yahweh (YHWH). Mark S. Smith says of this period, in The Early History of God, that according to the available evidence, Israelite religion in its earliest form did not contrast markedly with the religions of its Levantine neighbours in either number or configuration of deities. The polytheistic period prior to 722 BCE might better be referred to as ‘Hebrew religion’ rather than Judaism.
- During the late monarchic period, official Judaism developed in the direction of monolatry, although there is evidence that the ordinary people continued to worship gods and goddesses. This was Judaism, but scarcely recognisable today.
- At some stage during or after the Babylonian Exile, Judaism became monotheistic. Smith says (ibid), “Monotheism was ultimately a product of the Exile, but some developments leading to it are evident in a variety of religious expressions dating to the monarchy.”
Worship still revolved around animal sacrifices, so it was not the Judaism of today. The Exilic and post-Exilic period were when most of the Tanakh (Old Testament) was written or redacted, but the Talmud was centuries off in the future. - The destruction of the Jerusalem temple in 70CE brought animal sacrifice to an end and ushered in Rabbinic Judaism. The priesthood was abandoned and the teachings of the Pharisees seem to have been adapted to the needs of the time.
- Modern Judaism is heavily based on the Talmud, which is possibly as important to a Jew as the Tanakh. Synagogues have long since replaced temple worship.
The Hebrew religion of the early centuries of the first millennium BCE is scarcely to be called Judaism, but in any case arose from the Canaanite religion of previous centuries. At the other end of the timescale, the first version of Judaism that would have been recognisable to a modern observer, chiefly because of the books of scripture, only arose in the sixth century BCE.
The Jews encountered Zoroastrianism in Persia in the seventh century BCE, but it was already centuries old. It appears to have reached Persia from eastern Iran at least a hundred years beforehand. Views differ as to whether Zoroastrianism emerged farther to the east or in southern Russia, home also to Hinduism, with which it shares some affinity. I think the dominant opinion is that the origin of Zoroastrianism is in southern Russia, no later than about 1700 BCE. This is long before the evolution of Judaism and even before the legendary time of Moses."
