Final answer:
The mystery religion in ancient Persia formed around the sun god Mithra, which is distinct from the Zoroastrian worship of Ahura Mazda.
Step-by-step explanation:
The ancient Persian sun god around which a mystery religion formed was Mithra. This religion gained traction in the Hellenistic period when Greeks believed that Mithra could lead them to eternal life. This formed the basis of the mystery cult that was centered on Mithra, also known as Mithraism, which was characterized by secret rituals and initiations. Unlike the state religion of Zoroastrianism, which was focused on the worship of Ahura Mazda as the principal source of good and the battle against Angra Mainyu, the evil spirit, Mithraism revolved around the worship of the sun god Mithras, and it thrived on its enigmatic and esoteric nature. Despite the similar sounding names, Mithra and the religious figure Zoroaster are distinct; Zoroaster was a prophet who founded Zoroastrianism, whereas Mithra was the deity around whom the mystery religion developed.