Religion in the Parthian era
Despite ongoing studies by archaeologists, the religious characteristics of the Iranians of the Parthian era (founded in 247 BC - collapsed in 224 AD), like many other social and economic issues of that era, have not yet been clarified. It seems that the Parthians initially worshiped natural elements such as the sun, moon, and stars.
Source: Wikipedia — Religion in the Parthian era (CC BY-SA 4.0)