"The impact of particular Zoroastrian beliefs has been postulated on Greeks at (400 B.C.) - that is, on certain of the early Ionian philosophers, and on Plato and his school - and has been traced in some exilic and post-exilic parts of the Old Testament; but not until well after the downfall of the Achaemenians that doctrines appear in Jewish writings which eventually, in Pharisaic Judaism and Christianity, came to form an eschatological system markedly similar to the Zoroastrian one. This similarity naturally struck scholars as soon as the Iranian religion became adequately known in the West, that is, in the latter part of the 19th century; and, it was pointed out, it was all the more remarkable because of the absence of such eschatoalogical concepts in the Israelite religion. If Ezekiel 37 is regarded as metaphorical, than the earliest traces of these concepts among the Jews appear during what was for them the Persian period in their long history. On the purely historical plane, therefore, the natural deduction appeared to be that some Jews, learning of the beliefs held by their Zoroastrian rulers, came to consider these to be true, assimilated them accordingly..."
Boyce gave two reasons that the influence of Zoroastrian was underestimated: the expository portions of the Avesta are missing and other portions are not precisely dated and therefore the holy books of the Zoroastrians are ignored by Biblical scholars and secondly, that the Zoroastrians down to the 5th century A.D. generally worshipped without temples, altars or images. She mentions that the Book of Daniel contains characteristic Persian elements, in themes and vocabulary.
"Yet by now a quantity of obscure data has been amassed - the foundations of ruined temples, bits of inscriptions in Greek or Aramaic, wither excavated or preserved on stones set in later buildings' walls, brief legends or devices on local coins - which in sum establishes the presence of observant Zoroastrians down through the Hellenistic and into the Roman times in Eastern Mediterranean lands, flourishing unharassed under tolerant polytheistic rulers; and this supports the scanty but significant literary testimony to the same effect, from Strabo and Pausanias to Bishop Basil of Cappadocia, complaining in a letter of the obduracy of the Zoroastrians in his diocese, still in the fourth century A.D. worshipping faithfully there according to the ways of their ancestors, without dependence on books."
Boyce turns her attention to Sibyllists - poets who prophesy. "The Sibylline craft was traditionally concerned with untoward events, such as many revolutions and upheavals of Greek cities, many appearances of barbarous hordes and murders of rulers; and its practitioners were largely involved in interpreting these events, and natural disasters, as signs of the wrath of the gods, or portents of still worse calamities to come. The Persian Sibyllists had therefore a repertoire of words and phrases to treat of such themes; and they had only to wed these themes to the orthodox Zoroastrian doctrine of a triumphal end of time to be able to pour out dramatic verses, linking the direst descriptions of the Macedonian era with ardent prophecies of the eternal kingdom of Ahura Mazda which was to come hereafter. Later, when the Jews in their turn came to compose Sibylline oracles, they were able to draw in this respect on their own rich tradition of sombre prophetic denunciations of the evil ways of men."
"That the Jews were among those who studied these (Persian) works is proved by the fact that fugitive verses from the oracles of the Persian Sibyl, identifiable by their content, have been traced in certain of the Jewish-Christian Sibylline Books, which are the only Sibylline utterances of any length to survive."
"Another piece of evidence for the use by Jews of Persian Sibylline writings is the existence of a Jewish work in Greek called the 'Oracles of Hystaspes'. This not only kept the title of the lost Persian Sibylline work of that name, but also its frame-story, that of a dream dreamt by the Iranian king of old and interpreted to him by a young boy - possibly the youthful Zoroaster himself. The Jewish work, as it is known through citations chiefly by Lacantius, is again thoroughly Hebrew in character, linked to the Old Testament by names and themes, and with the new hopes and expectations which it expresses developed in accordance with the old prophetic tradition; but the title and frame-story show that when the Jewish 'Hystaspes' was composed that a link with Zoroastrianism and its ancient legends still carried authority for learned Jews, helping to authenticate the work; and still in the final redaction a few lines survive embodying the Zoroastrian doctrine of the destruction of sinners at the Last Day. This doctrine, and other distinctive Zoroastrian elements, are to be found also in the Jewish intertestamental writings."
Three comments by Mark Willey on the above:
1. One reason that Jews and Christians don't recognize the influence of Zoroastrianism is ethnocentrism or bigotry. They deny that their religions are greatly influenced by any other culture and after all, since these religions were revealed, bigots have no logical necessity to look for outside influences.
2. Boyce calls Old Testament themes "thoroughly Hebrew in character" without considering that the Old Testament may be Zoroastrian in character. She seems to ignore Professor Dr. Friedrich Spiegal's point in Avesta die Heiligen Schriften der Persens (Wien 1853) that Genesis is just a mass of Zoroastrian myths; Leviticus and Deuteronomy are from the Vendidad, and that many Old Testament books are from the Persian period and all were written under Persian control. So, to claim some themes are Old Testament in character is to beg the question of whether the themes are Hebrew or Zoroastrian.
3. One suggestion of Boyce's, which came just after the second paragraph quoted above, was that since Jews and Zoroastrians were living side-by-side for centuries and both spoke GREEK, that that may account for the Zoroastrian influence. Before the Persians took Israel, the Jews spoke Hebrew, a Canaanite language. Under the Persians they spoke Aramaic - one of the official languages of the Persian Empire. One does not need to look to the Hellenistic period or later to find that the two nationalities could communicate - they both spoke the same language for the hundreds of years that the Persian theocracy controlled the Jews.