They had multiple deities who covered the spectrum of human activities. We are more economical today.
Chat with our AI personalities
Both were polytheistic - having many gods with different areas of power.
Persian Empire.
The Greek world had a fairly uniform religion and set of gods. The Persian Empire, stretching from Egypt to central Asia, covered a wide variety of peoples and religions, and it was not the Persian policy to incite religious revolts when they were trying to establish a peaceful and prosperous empire.
Multiple gods each with their sphere of influence in human affairs, in an unscientific world where unknowns were given a religious answer. Even today, when we have scientific answers people still use the god answer.
It was merely a Persian religious sect which did not have a political influence. The Persian Empire was divided into 20 provinces (satrapies) with a Persian governor (satrap), overseen by the king and his council, an entirely practical approach, not a religious one.