Little Kourosh, with the knowledge he had brought from the twenty-first century, knew well that religious institutions, if left unchecked, could become an independent power and even a rival to the state, as the Christian Church in Rome and the Islamic Caliphate demonstrated in later centuries. He was determined to keep his Persian empire safe from this danger. Therefore, he designed a religious structure in which temples and fire temples had neither the right to own land nor the permission to accumulate independent wealth. All their expenses, from maintaining the sacred fire to the livelihood of the priests, were provided from the budget of the satrapies, a budget that was directly under the supervision of the emperor and the governmental council. This financial dependence turned the religious institution into a loyal arm of the government and prevented any financial, political, or military autonomy. Kourosh also enacted laws that any commercial activity by the temples, such as selling gifts or religious services, was only possible with a government license and under strict supervision, so that no loophole for the accumulation of power remained.
At the heart of this religious organization was the central temple of Damavand, which acted as the spiritual axis of the empire and housed the great Zoroastrian fire temple. This temple, with its golden dome and marble walls, was a symbol of religious unity and the connection of all faiths under the banner of Ahura Mazda. In each satrapy as well, a central temple was built in the main city, which had a smaller but magnificent fire temple and was administered under the supervision of the satrapy's chief priest. These local temples not only met the spiritual needs of the people but also served as cultural and educational centers, where priests promoted Zoroastrian ethics and literacy. This hierarchical structure, with the Damavand temple at the top and the satrapy temples as its subordinates, ensured that all religious activities were coordinated with the central policies of the empire and that no local temple could become an independent center of power.
At the head of this organization stood the Chief Priest (Mobed-e Mobedan), who had a role similar to the Pope in Christianity, as a symbol of the empire's religious unity. But unlike other traditions, he was chosen by the emperor himself. Every 10 years, the emperor would form a council of the wise, including senior priests, philosophers, and representatives of the satrapies, to propose worthy candidates. These candidates were tested in rigorous examinations of religious knowledge, Zoroastrian ethics, and loyalty to the ideals of the empire. The final decision, however, always rested with the emperor, which consolidated his authority over the religious institution. In each satrapy as well, the satrapy's chief priest was chosen every ten years from among the local priests, again by the direct choice of the emperor or his representative, so that the religious hierarchy remained completely under central control. This structure, inspired by the organization of Christian bishops that Kourosh knew from the future, prevented any concentration of power in the hands of local priests, and each individual could hold these religious positions for only one term.
The priests in this system had purely spiritual and cultural duties. In the temples, they taught the principles of worship and Zoroastrian ethics—Good Thoughts, Good Words, Good Deeds—to children and adults. In the academies, they taught religious philosophy and religious history, an approach that Kourosh had strengthened with his modern knowledge. The priests also served as moral advisors in the local councils, helping to resolve disputes with reliance on justice and truthfulness. The life of a local priest was as such: in the mornings, he would teach the village children to read and write; in the afternoon, he would participate in a wedding or funeral ceremony; and at night, he would assist the village headman in resolving conflicts. This multifaceted role turned the priests into the cultural and spiritual arm of the empire, but they were never allowed to interfere in political, military, or economic affairs, and any transgression was met with immediate dismissal by the satrapy's chief priest.
Kourosh, aware of the divisions that different interpretations of sacred texts created in the future—such as the multiple versions of the Torah and the Bible—compiled a final and comprehensive version of the Avesta after coming to power. He gathered all the hymns, prayers, and Zoroastrian teachings with the help of senior priests and, using the New Persian script and movable type technology, turned it into a single, unchangeable text. This book, which included religious and ethical principles, and even guidelines for the coexistence of religions, would become the official reference of the empire. Kourosh intended to order that every temple keep a copy of this book in its library, and every priest was obliged to base his teachings on it. In the future, when a priest in the satrapy of Lydia tried to offer an arbitrary interpretation of the Avesta, the satrapy's chief priest dismissed him by citing the Avesta, and this example showed how effective Kourosh's system was in preventing deviations.
To ensure greater unity, Kourosh created a permanent council called the "Council of Light," which was responsible for the periodic collection and preservation of the Avesta. This council, composed of chief priests from all over the empire, reviewed any interpretation in the religious texts, but every interpretation required the final approval of the emperor. This mechanism, on one hand, provided the necessary flexibility to adapt to the times, and on the other hand, prevented any distortion or abuse. Kourosh also ordered that the priests gather periodically at Damavand to receive comprehensive training. These gatherings, which were accompanied by prayer ceremonies and philosophical discussions, strengthened the sense of unity among the priests and kept them committed to the ideals of the empire.
He also brought women into the religious organization, training female priests (Mobedeh) who would teach women and children, especially in remote areas. This progressive view, which stemmed from his modern knowledge, not only elevated the status of women in society but also helped to spread literacy and culture. Kourosh also taught the priests to explain natural phenomena like thunder and lightning as part of Ahura Mazda's creation, not as signs of the gods' anger, to eradicate superstition and blend faith with reason. This approach, a combination of spirituality and rationality, gave his empire a distinct identity.
The priests served as moral advisors in the local courts, but the final judgment was always with the secular judges, so that religious power would not influence judicial affairs. The temples, although they had no independent wealth, earned a limited income from the sale of copies of the Avesta or religious works like printed prayers and hymns, under government supervision, and this income also returned to the satrapy's treasury. Kourosh even ordered that the priests regularly submit performance reports to the satrapy's chief priest, and these reports were sent to Damavand to prevent any deviation or abuse. This religious organization, with its combination of spiritual unity and central and local control, would not only unite the empire but also guide it towards an eternal civilization in which religion was not a tool for power, but a lamp for guidance.