Religion was a major contributor to the Byzantine Empire Because it shaped the culture and the military. but on the the hand it also divided the nation because there were Christian's, Jews and...
Byzantium's main influence was in Anatolia, what is modern day Turkey. Even at it's peak the Byzantine Empire wan't very large, but its borders were constantly being compromised by nomadic Turkic...
The adoption of the Byzantine Christianity affected the roman empire by helping them form their own type of religion and changing the way people saw their everyday lives.