Gauging the importance of religion to the exercise of political will inthe Sasanian world requires enormous care. It is all too easy to takethe Great Kings at their word as they championed the doctrines ofZoroastrianism in their political pronouncements, especially as someof them also persecuted Christianity. Whether or not such sentimentswere genuine, a closer analysis of the evidence suggests a more pragmaticroyal use of religion. The political realities on the groundwere more often the deciding factor in how the kings related to thereligious sectors of Sasanian society. This state of affairs sometimesset the kings against the Zoroastrian clerics, whose agendas werenot always in alignment, and it explains why Christian persecutionswere usually motivated more by politics than doctrine. Moreover,this dynamic also explains the prominence of the Christian church inthe later Sasanian period as kings employed it as a base of support,much as they had the Zoroastrian hierarchy.
Patterson, Lee, "Minority Religions in the Sasanian Empire: Suppression, Integration and Relations with Rome" (2017). Faculty Research & Creative Activity. 238.