The Scriptures and Authority
The sacred text of Zoroastrians is the Avesta. It was preserved orally for some time and then written down in a specially designed alphabet. It is known from summaries in later texts (the Pahlavior Middle Persian literature) that we have only about a quarter of the original. It was collected in the third century CE and was preserved because it was liturgical material in a ritual setting.
For Zoroastrians religious authority rests fundamentally on the vision of the prophet Zoroaster contained in his hymns, known as the Gathas. These are found in the Avesta.
Some of the books in the Avesta, notably the Yasna, are the text of the liturgy of that name. At the heart of the Yasna, the Gathas (the original 17 hymns of the prophet Zoroaster), are preserved. In these, Zoroaster recounts, in poetic form, his visions of Ahura Mazda and the teaching he was given. He declares that there are two contrasting forces of good and evil in the world, and sets forth his belief in the Seven Bounteous Immortals (Amesha Spentas). These are the creative spirit, qualities of Ahura Mazda in which humans can and should share, for example Good Mind (Vohu Manah) and Righteousness (Asha). Other books in the Avesta give ritual directions, for example, on purity. Avestan is the sacred language of prayer for Zoroastrians; it is the language of visions thus making them spiritually powerful.
The Middle Persian texts were produced after the Islamic invasion of Iran in the 7th century. Some of them are basically collections or summaries of Avestan material in translation on a set theme. One, the Bundahishn, meaning creation, tells the story from the creation right to the last days. Zoroastrians do not call this the end of the world, as its end would be the defeat of Ahura Mazda (Ohrmazdin Pahlavi). They refer instead to the Renovation, (Frashegird) as creation is restored to its original perfect state once evil has been defeated and all people are raised from the dead. After this second judgment all will be punished or rewarded before finally dwelling with Ahura Mazda. The soul is judged at the bridge of judgment, the Chinvat Bridge, after death, when everyone’s good and evil thoughts, words and deeds are weighed in the balances.
Other books include exhortations to be faithful to the religion in the face of persecution, and theological expositions of key doctrinal issues such as human nature and duty. The Pahlavi (or Middle Persian) texts are taken as authoritative by most Parsis but Iranian Zoroastrians tend to look past them and turn only to the Gathas, viewing these as the word of the prophet.
It is widely thought that Zoroastrianism influenced Christianity and Judaism with the beliefs in angels, demons, heaven, hell and the resurrection of the dead.