As I have said before, I regard the Eastern Roman (Byzantine) Empire as the high point of Christian devoutness in human history - certainly not perfection nor paradise, but the high point - and from this follows certain conclusions which frame quite a large range of other historical matters.
1. The Great Schism, that process around 1000AD when the Western and Eastern churches divided, is seen as a disaster; but especially for the West. From that point Western Christendom has been significantly incomplete and biased (and the East, also, was wounded and diminished). This does not (in my view) at all mean that the Western Church is invalid - but that its capacity for glory has been lessened, it cannot reach the heights of theosis which previously had been possible, nor can the Christian life on earth be as complete as it was in Byzantium.
2. The Reformation was seriously flawed by (in some instances) its explicit denial of so many tenets of the ancient Eastern church - monasticism and the eremitic tradition, iconography, veneration of the Mother of God etc - in other instances these were neglected but not outlawed by reformers. By the standards of those who regard Byzantium as the apex, the Reformation and all its consequential ramifications has been a very clear failure in terms of the level of devotion (the level of theosis) it was able to create and sustain.
3. In politics, the supremacy of Byzantium refutes any doctrine or notion that the institutional division of Church and State is necessary or desirable (although in some circumstances it may be the least bad option). It refutes the supremacy and even desirability of democracy, socialism, libertarianism and a host of other modern fetishes. Indeed, Byzantium demonstrates that such institutions as slavery and eunuchs are not qualitatively outwith the scope of a high Christian civilization. Tough stuff.
4. Byzantium also refutes the idea that a civilization ought to be judged by its achievements in science, literature, the arts, military conquest, economic growth or any other worldly domain - and implies that all of these should be subordinated to the spiritual and next-worldly as the primary and explicit goal of civilization.
5. The history of the world is seen as having been in decline for many centuries - indeed since at least the sack of Constantinople by Latin Christians in 1204, leading up to the end of the Third Rome with the execution of Tsar Martyr Nicholas II in 1917.
(Unless Holy Russia can be revived...) The thread of Christianity in this world has been broken, and its wholeness almost everywhere broken; and all remaining Christian possibilities are intrinsically much limited in scope.
This explains why the highest peaks of Holiness seem to be very limited in our era (perhaps no living Saints in Europe, UK or the USA?), and probably this situation cannot be remedied.
Yet limitations in scope and nature do not affect the duty to be a Christian nor the duty to strive for sanctity, nor do they diminish the need for mission and conversion. We are still afforded glimpses of Heaven. But our situation does diminish the fullness and height of what can be attained.
I could go on - but it can be seen from these examples that a Christian spirituality which sees Byzantium as the apex of devoutness on earth will have widespread implications beyond the acknowledgement of a simple historical fact.