The development of Eastern Christendom was characterized by the gradual perfusion of the existing pagan society with Christianity, rather than a rupture. Even during the Latin Middle Ages when the ecclesiastical and political powers were most closely connected, the West distinguished the roles of each realm. And after the close of the medieval era, this distinction hardened into a rigid separation as the civil power asserted its independence from religious values. But in the East, the strict dialectic of sacred vs. secular that developed in the West following the clash of the Christian and pagan worldviews did not appear. Apart from a brief period in the Middle Ages when the politico-religious system attained a delicate balance, there was constant conflict of Pope and Emperor. But in the East, the spiritual arm from ancient times has been integrated with the temporal arm to where the two institutions came to operate in company.
Here is the Byzantine doctrine of symphonia: that the clerical and civil powers should work together as equal partners in the administration of Christendom. The benefit of this model is that it preserves and honors the role of the laity not merely in earthly business and governance but also in the affairs of the Church. It is a mark of how far we have departed from synthesis that even our language divides between “Church” and “State” as if they are separate, opposed realities. In truth, as all Christendom once realized, there is only one entity: the Church, Mystical Body of Christ, composed of spiritual and temporal arms in harmony. There is no autonomous, secular State, but one Church placed over all society whose members fulfill different roles according to their particular state in life. The laity are charged to order society on the natural level according to reason, and the clergy are called to sanctify it through the supernatural grace of faith.
However, this Byzantine theory did not work out perfectly in practice because it often became entangled in confusion about the roles of the respective powers. This was due to the real-world conditions in Eastern Christendom, dominated variously by empires (Eastern Roman, Russian) and Mohammedan oppression. What ended up happening was that the lay power usurped the authority of the clerical power by meddling excessively in ecclesial matters outside its scope. And in some cases, this interference reached the point where even the freedom of the clergy to act independently from the civil authority was compromised. This reality, called Caesaropapism, is a major factor behind the drift apart and schisms of the Latins and Greco-Byzantines beginning over a millennium ago. And in the 20th Century, this subordination aided the Bolshevik subversion of the Russian Orthodox Church, which is now happening again with Putin’s regime.