Zoroastrian god, Ahura Mazda
Mithraic depiction of Zoroaster located in Dura Europos, Syria by Franz Cumont, 3rd century
Relief of Ahura Mazda, Persepolis, c. 500BC
Zoroaster · Zarathustra
Zarathustra, as he was well known in Iran, was an Iranian prophet and reformer of the ancient religion of Iran. Outside of Iran, he was known as Zoroaster, which is the Greek translation of his name. Zoroaster, aka Zarathustra, was said to have been the Iranian/Persian priest-turned-prophet who challenged the traditions of the Iranian religion at that time and ultimately founded the religious movement that came to be known as Zoroastrianism (devotion to Mazda), and the first monotheistic religion.
Zarathustra, whose name means owner of gray camels, and his family were part of a nomadic pastoralist society. There is no true consensus of when he lived, where he was born, or existing family lineage, but it seems the dates of 7th-6th century BCE are commonly accepted for the time period that he may have lived, preached and founded Zoroastrianism. The only evidence and only sources of info on Zarathustra comes from references in the Avesta, but did not particularly cover details of his life nor the people he may have interacted with; and to further complicate the matter, once Zoroastrianism was widely accepted, regions and countries started to claim Zarathustra as their own.
It is said that Zarathustra was a priest in the ancient Iranian religion by the age of 15 after being educated at an early age, suggesting perhaps that his family may have come from significant means for him to not have been sent off to work or taken up another profession that would have economically contributed to the family. He leaves home possibly by age 20 as a devout priest to the Early Iranian Religion or the Ancient Persian Religion (what it's called today), the polytheistic belief where many gods were presided over by Ahura Mazda. Then, at the age of 30 - still a priest for the Early Iranian Religion/Ancient Persian Religion - attended the festival of the Rites of Spring, where it is said he began to have visions of the god Ahura Mazda as he said prayers by a river.
Another theory states that on the riverbank, an entity formed as a bright light appeared calling himself Vohu Mahah, saying he had been sent by Ahura Mazda to deliver a message that the religion of the people was being practiced wrong. Ahura Mazda was not interested in animal sacrifices but in moral behavior. He told Zarathustra that he had been chosen by the One True God to preach the news and bring proper understanding with the Divine. Zarathustra claimed to have received messages in the form of answers to questions while in deep prayerful meditation, memorizing them, then repeating them to his disciples as a living scripture passed down through the generations in the ancient language of Avestan. It wouldn't be until after several years of preaching his new found belief system that he gained the support of King Vistaspa and ultimately helped Zoroaster spread his belief. Under King Cyrus the Great, Zoroastrianism became the state religion, continuing under the Persian Empires that followed. It was claimed that Zarathustra married 3 times and either died of natural causes at 77 or assassinated by an opposing priest in retaliation for dismantling the religion of old.
The Early Iranian Religion kept oral tradition, therefore nothing was recorded in written word regarding rituals of these previous beliefs. When the Zoroastrian faith was adopted during the Achaemenid Empire (550-330 BCE) leading to be later adopted during the Parthian Empire (247 BCE - 224 CE), it wouldn't be until the Parthian Empire that a written record would come to light, documenting the conversation between Zarathustra and God. The written form of the oral tradition became known as the Avesta (Zend Avesta) - describing the vision of a single, all-powerful, all-good God who took a personal interest in the lives and mortality of human beings.
The only description of the rituals performed prior to this new monotheistic belief, came from Zoroastrian scriptures and the Avesta (old Iranian language), describing the existence of a priestly class (Magi) and worship conducted outdoors on shrines known as Fire Temples. Sacrifices in the form of grains, animals, precious metals and objects - the very ones Ahura Mazda would later convey to not be interested in - were offered up but somehow also became the property of the priests presiding over these altars, who grew wealthy from these offerings and subsequently acquired control of the best farmlands.
Zoroastrianism is arguably the world’s oldest monotheistic religion founded by the Prophet Zarathustra and to date, appears to have been the first religious thinker to conceive an eschatological mythos concerning a future saviour rescuing the world from evil. The Day of Judgement was central.
Zarathustra was said to have instructed Pythagoras in Babylon, inspiring Chaldean doctrines on astrology and magic, thus earning him the title as founder of astrology and magic. All that is most reliably known is that Zarathustra lived in eastern Iran, away from the more civilized portion of western Asia, prior to Iran’s unification under Cyrus II the Great. While he does not mention Achaemenids nor the Greek historian Herodotus, Zarathustra’s doctrine must have reached western Iran prior to the time of Aristotle (384-322 BC), who alludes to dualism. Then in the 1st century BCE, the first proof of the Zoroastrian calendar in Iran surfaces as well as gods bearing combinations of Greek and Iranian names. His theory and essentially the framework on dualism had exact counterparts. Zoroastrianism at its core was not insistently monotheistic as compared to Islam or Judaism, however, it represented the original attempt to unify the worship of a supreme god against the backdrop of polytheism, comparable to those at the time (Greeks, Latins, Indians, etc). Dualism was the other outlining feature of Zoroastrianism, with good and evil fighting an unequal battle. This concept was established and elaborated well upon in Zoroastrianism and may have been influential in messianic beliefs such as Judaism.
Ahura Mazda (Wise Lord) was most likely the chief god of pre-Zoroastrian; alongside Ahura Mazda, Mithra (became a common word for sun) was also considered important and possibly occupied equal position. Worship of the gods happened out in the open and is still performed by Zoroastrians and Hindus in what could be considered the oldest continuously enacted ritual known. These rituals were conducted in order to enter into communion with a divine being for a specific purpose.
Zoroastrians don't often believe they are leading free and moral lives despite their doctrine of free-choice. Ahura Mazda and these beings of light kept the dark force Angra Mainyu, his legion of demons and spirits of darkness at bay in a never-ending conflict for control of the world. In between were humans and their free will to choose either: The Path of light and love by submitting to the will of Ahura Mazda and live well on earth & assured afterlife in paradise OR Join in the rebellion w/ Angra Mainyu, corrupt what was good w/ selfishness, spend life vainly attempting to find happiness in the misery of others and pass on to a dark hell after death. Ahura Mazda’s granting of power of choice to humanity - there was nothing more powerful that not even Ahura Mazda could or would try to subvert it.
Central to Zoroastrianism is its monotheistic and dualistic features, with dualism, angelology, and eschatology as the pillars of their belief system, which would go on to heavily influence Judaism, Christianity, and Islam. Zoroastrianism was the ancient, pre-Islamic religion of Iran and its influences have impacted people such as Voltaire, Nietzsche, Freddie Mercury as well as serving as an inspiration for George R.R. Martin’s Game of Thrones’ character (Azor Ahai/Lord of Light) and the car brand Mazda.
A notable mention are the striking parallels that exist between Isaiah 40-48 and 3rd-4th verses of Gatha 44, where the notion of God who created light and darkness is a theme that is only seen in 2 prophets: Iranian (waking and sleep) and Isaiah (good and evil) with the Creator God being common to all western religions. In addition, the Zoroastrian doctrine also had a variant of the Noah’s Ark mythos.
Avesta Manuscript ADA 4050, Corpus Avesticum Berolinense, Iranian National Library
Opening to Ch.9 of Videvdad Sadah, Avesta British Library
Fol. 124, Illuminated Avestan Manuscript 4062 from Mobad Mehraban Pouladi Collection, Tehran