Final answer:
Zoroastrianism became the state religion under the Sasanian Empire, emphasizing a monotheistic belief system with a dualistic vision of good and evil. It influenced the structure of society, promoting unity under a single faith and justifying the empire's expansion. Despite the eventual conversion to Islam, traces of Zoroastrianism, like the Nouruz festival, endure in modern Persian culture.
Step-by-step explanation:
The division of society when Zoroastrianism became the state religion under the Sasanian Empire involved different social structures and religious practices. Zoroastrianism emphasized the constant battle between good and evil, represented by Ahura Mazda and Ahriman, respectively. This dualism reflected in society with the belief that individuals played a critical role in the cosmic struggle through their actions. Ardashir, the first king, and subsequent rulers used Zoroastrianism to justify the political and territorial expansion of the empire.
Zoroastrianism was distinct in several ways. It was a monotheistic faith with dualistic elements and had an ethical code that emphasized good thoughts, words, and deeds. It also had a significant spiritual component, with the prevention of slavery, the presence of fire temples, and rituals of purification governed by priests known as magi. Unlike other ancient religions that were polytheistic, Zoroastrianism's structure helped to align society under one spiritual and governmental regime where the kings were considered earthly representatives of Ahura Mazda.
Moreover, Zoroastrianism's egalitarian principles shaped social organization by presenting the idea of equality before God and offering all believers the chance for salvation. The eventual conversion to Islam marked a significant transition in society, but elements of Zoroastrianism, like the celebration of Nouruz, remain influential even today. Its significant implications for personal conduct and its anti-slavery stance stood in contrast to existing traditions in contemporary societies like ancient Greece.