"In ancient India, Iran and elsewhere, Dumezil found that the 'ideology' of a tripartite division of society parallel to a tripartite classification of the gods was prominent.... Among the Aryans, then later the Indians, Mithra and Varuna represented respectively the juridical and magical aspects of the first function, the province of priests. The second function, the martial spirit or force, was the domain of the warriors and the god Indra, while the third function, that of fecundity or growth, was the concern of farmers and husband men."
"From cuneiform sources one could surmise that Aryan bands first came into Mesopotamia with the general movement of peoples after the death of Hammurabi in the seventeenth century BC. This is also the time of the expansion of the Hurrians, a people whose linguistic and ethnic affiliations are puzzling; in any case, they are not Indo-Europeans. They formed an important empire called Mitanni, and it is principally among the Mitanni that Aryan names and words occur....In a famous treaty between the Hittite ruler Suppiluliuma and the Mitanni king, Mattiwaza, about 1370 BC, the Aryan gods Mithra, Varuna, Indra and the twin Nasatyas are mentioned. Thus in the Mitanni kingdom Aryan gods were worshipped as well as Mesopotamian deities, which would indicate an Aryan element, but probably only among the rulers."
"Since the Aryan bands in India fought among themselves as well as against the non-Aryans in Iran, and there must have resulted considerable mixtures of various peoples."
     - Richard N. Frye, The Heritage of Persia

"As other discovered texts proved, the Hittite pantheon was in fact borrowed from (or through) the Hurrians." A particular treaty, between the Hittite King Shuppilulima and Mattiwaza, king of the Hurrian kingdom of Mitanni circa 1350 BC, however, listed among the divine witnesses "Mitra-ash, Uruwana, Indra, and the Nashatiyanu gods, the very Mithra, Varuna, Indra, and the Nasatya gods of the Hindu pantheon!"
     - Zecaharia Sitchin, The Wars of Gods and Men

"Zoroaster (628-551 BC?) was probably a priest of the old Aryan religion, for he calls himself a zaotar (Indian hotar) in the Gatas (Yasna 33.6)....He also retained the old poetic form, for the meter of his Gathas is similar to that of the Vedas. He further exalted the concept of asha, 'truth', the rta of India, and further used words in the same sense as in the Vedas."
"The deity is like a partner in discourse with the prophet, and this is new with Zoroaster."
"...The adherents of the old Aryan religion were more rites centered and the adherents of Zoroaster, perhaps to be designated as Aryan reformers, more belief centered."
     - Richard N. Frye, The Heritage of Persia

"Zarathustra [Zoroaster] was the son of a priest of a pastoral tribe. As a boy he showed much concern for others and was deeply interested in finding the truth of religion. At the age of thirty, or a little older, he had a decisive religious experience in which he encountered the angel Vohu Manah (literally 'Good Thought'), an aspect or emissary from God. The angel transported him in spiritual form to the great spirit 'Ahura Mazda', the 'Wise Lord' - henceforth Zarathustra's name for God. This prophetic experience was followed by other revelations in the next decade of Zarathustra's life. As a consequence, he felt called to preach a purified faith against the existing polytheism (which had some similarities to the related religion of the Aryans...)"
"The god whom he addressed as Ahura Mazda had attributes, both ethical and celestial, of the sky god Varuna, a focal figure of Vedic religion...But the indigenous religion of early Iran entertained belief in a host of other gods and spirits - Mithra, Vayu, Yima, the fravashi, and so on. Zarathustra....equated the gods with evil spirits, who seduced men from the true worship of the one Spirit....He often mentioned Druj, the 'Lie', which was an evil force waging a struggle against Ahura Mazda....The chief evil spirit in the service of Druj was Angra Mainyu."
     - Ninian Smart, The Religious Experience of Mankind

"No longer shall the evil teacher - Druj that he is! - destroy the second life,
In the speech of his tongue misleading to the evil life.
     - The Gathas

"Zoroaster's cosmology was based on the concept of a struggle between good and evil. Zoroaster said that this struggle was to take place over a period of 12,000 years divided into four stages. The first stage consisted solely of spiritual existence during which time a chief god designed the physical universe. During the second stage, the material universe was created, followed by the entrance of the chief god's opponent into the new universe for the purpose of creating problems. The third phase consisted of a battle between the chief god and his rivals over the fate of the many souls who came to occupy the universe. In the fourth and final stage, the chief god was to send in a succession of saviors who would finally defeat the opponent and bring salvation to all spiritual beings in the universe. According to Zoroaster's model, the world is in the fourth stage."
     - William Bramley, The Gods of Eden

"The ethics taught by Zarathustra were based on the social life of the husbandman. The good man is one who looks after the cattle and tills the soil in peace and neighborliness. He is upright and has a burning regard for the truth. It is his duty to keep away from those who worship the daevas and to resist them with force if necessary. Angra Mainyu, the great evil spirit, threatens the farmer's life."
     - Geoffrey Ashe, The Ancient Wisdom

"Zoroaster know that his people had been honoring familiar gods for centuries, however, so he recast some of them as 'bounteous immortals', or angels; the rest he condemned as demons."
     - Cosmic Duality

"The dead one would approach the Chinvat Bridge, which crosses to Ahura Mazda's paradise. Below it hell would yawn. If a man's good deeds outweighed his bad ones, he would be beckoned onward and could cross the bridge with ease. But the wicked would find it impossible and topple over into the regions of punishment."

"The chief ritual of Zoroastrianism, the fire ceremony, seems to have derived from the earliest times in the Zoroastrian tradition - perhaps from Zarathustra himself, who, according to later tradition, was killed while performing the fire sacrifice. There is little doubt that Zarathustra was adapting and attempting to purify the old Aryan fire sacrifice, which had centered on the figure of Agni in the Vedic hymns."
In the fire temples of the Parsees in modern India, "the sacred fire is maintained continuously in an inner chamber of the temple by priests who wear special protective cloths over their mouths to prevent contamination of the pure fire. Worshipers come to the threshold with their offerings, and receive in return ashes from the sacred fire. A more spectacular custom is the Parsee method of disposing of the dead: corpses are not buried or cremated, but are placed upon the famous 'Towers of Silence' where vultures pick the flesh and the sun bleaches the bones, which are later thrown into a central well. In this way the sacred elements are not defiled by the corpse."
     - Geoffrey Ashe, The Ancient Wisdom

"The ancient Chaldeans devoted great attention to magic. In the British Museum are over 200 magical tables containing formulas for the Chaldean magical processes that were originally prepared by King Ashurbanipal and written in two languages, Assyrian and Accadian. They are a mixture of both high and low magic; much of the teaching is concerned with demonology, magical charms, amulets, and diviniations."
     - Geoffrey Ashe, The Ancient Wisdom

"One should not be led astray by the wide use of 'Magi' in Hellenistic and Roman times for priests of Mithraism and many other religions or sects. One may tentatively suggest that the Magi were a 'tribe' of the Medes who exercised sacerdotal functions. During the supremacy of the Medes they expanded over the Median empire as a priesthood since the priestly trade was kept, so to speak, 'in the family'. The theogonies they sung were the ancient hymns of the Aryan Urzeit, not well understood by Medes or Persians but impressive because of their antiquity."
     - Richard N. Frye, The Heritage of Persia

"According to one tradition, Zarathustra converted a king called Vishtaspa, or Hystaspes in the Greek transliteration, who was a ruler of parts of eastern Iran. His conversion was crucial in the spread of Zoroastrianism because Hystaspes was the father of Darius the Great who, in turn, became a strong exponent of the religion."
"During the Achaemenid dynasty there developed a tendency to restore the cult of lesser deities within the framework of Zoroastrian belief in Ahura Mazda's supremacy. The Amesha Spentas, for instance, were ore and more personalized. the fravashis, or ancestral spirits, though they were identified with the highest part of the human personality, and so entered into the later doctrines of immortality, were restored in the form of guardian angels....The Magi had opposed the Zoroastrian movement when it first spread through Persia. They were drawn into the new religion because of their excellence as priests and magicians. The magi imported into Zoroastrianism certain practices that gave the faith a character more ritual and magical than ethical. The latter portions of the Avesta have much to way about spells and incantations....There was a considerable proliferation of the mythology of evil: a whole hierarchy of spirits were ranged under the leadership of Angra Mainyu."
     - Ninian Smart, The Religious Experience of Mankind

Developments in Zoroastrianism have "been obscured by the changes that followed the conquest of the Persian Empire by Alexander the Great, especially the establishment of many smaller Greek dynasties in plane of the Great Empire. The period, which started effectively under Mithridates I, in the second century B.C., and which lasted down to the Parthian era, brought about a further syncretism within Zoroastrianism. One effect of this was the rise of Mithraism...The Sassanian dynasty, which destroyed the Parthian supremacy, lasted from the early part of the third century A.D. until 651, when it was vanquished by the Muslims."

According to the Zoroastrian theory of history elaborated during the Sassanian dynasty, "time can be divided into four eras, each of three thousand years....The fourth era begins with the sending by God of his prophet, Zarathustra, to help mankind. Zarathustra's fravashi [everlasting prototype] had already been created in the second period, so that his soul dwelt in the realm of the transcendent before it was clothed in human flesh at the time of his earthly life. After Zarathustra, every thousand years during the remainder of the era spiritual successors came into existence. These saviors will culminate in Soshyans, who will prepare the way for the resurrection of the dead. In a final combat, the forces of evil will be put to flight and destroyed. The universe will be restored in a purifed state: men and other creatures will be made immortal, and join in the praises of Ahura Mazda."

"...Despite the virtual demise of the religion in its homeland, it contributed to the stream of western religious history. In eastern thought the Zoroastrian idea about later Saviors who would help mankind played some part in the rise of the Bodhisattva cult in Greater Vehicle Buddhism. Traders and travelers must have exchanged ideas about religion as they followed along the silk routes of Central Asia to China. It is probable too the Mazdaean magical ideas entered into later Taoism, through Chang Tao-ling. Oriental ideas transversely contributed to Manichaeism..."
     - Ninian Smart, The Religious Experience of Mankind