In the 500s before Christ, the Iranian ("persian")Empire conquered all of the Near East and much of North India, Central Asia. The emperor which conquered the middle east, Kurosh (Cyrus), set the hebrews enslaved in Babylon free and let them return to Israel, the Tanakh/Bible calls Kurosh thus mashiakh (messiah), the anointed one. The Iranians did not impose their religion (Zoroastrism) to others, but usually tried to subvert them. Ezra and Daniel were employees of the Empire and especially Ezra or people associated with him are the most likely to have put hebrew oral tradition in written form and edit those writings into the first issue of what we call the Old Testament/Tanakh: Torah, Neviim and Ketuvim (Law, Prophets and Writings), of course some of the books in Ketuvim appeared later. Elements such as angels, good vs. evil, heaven vs. hell, judgment day were absent from the Torah, which tells the oldest hebrew/Abrahamic traditions. In the Torah, the souls of the dead went to Sheol, no matter what. Zoroastrism had angels, good vs. evil, heaven and hell and judgment. Those elements thus probably got into hebrew belief by Iranian influence. The very belief that there is only one God and all others are imagined is more Zoroastrian than early Abrahamic, since the Torah and some other books hint at the interpretation that only one god is worthy of praise, the other gods exist but are unworthy. Well, this is a theory I read. What do you think?