When the Roman Empire Christianised under Constantine I and moved its powerbase to Byzantium (Constantinople, later Istanbul) in the 4th century CE, there was a clear shift in power towards the worship of Man as spiritual overlord of mankind, a shift that had commenced with the pagan Emperors three centuries before, and attained its Christian dimension with the Councils of Nicea and the development of the Nicene Creed which identified Jesus as God. The main threat to the theological establishment of this form of Christianity within the Empire during the 4th century was a movement called ‘Arianism’: The Arians (named after their main apologist – a northern African theologian named Arius) effectively rejected the idea that Jesus was anything more than a prophet of the new Middle Eastern God who had been chosen to rule the Romano-Greek Empire – a radical reinvention designed to settle its divisions. Although suppressed under Constantine, Arianism had a brief resurgence in the mainstream following his death, when many (not the least his son and successor Constantius) were uneasy about the Emperor’s use of the Nicene interpretation to promote the Imperial Godhead. During this period, (Arian style) Christianity came to and spread rapidly through the Germanic world of the Goths (Gutani). These were peoples which Rome had largely failed to conquer by military might but had formed strong alliances with through treaty, and whose men manned many of Rome’s legions. So … why might Arianism have been so successful among these pagan peoples?
One of the main reasons may have been that the foregoing philosophy of paganism would have considered the worship of a man as a complete heresy and anathema. For the Byzantine Roman Empire created by Constantine and later consolidated by Theodosius, the primacy of man was critical to the power of the re-invented Theocratic rulers – one God, one Emperor, one Empire. This structure also served the religious hierarchs who ruled the Christian polities out of Rome, Alexandria, Jerusalem etc
Arians such as the Gothic warlord and Emperor Alaric were deeply disillusioned by what they found when they conquered the Western Roman Empire, perhaps just a little disillusioned too by the Eastern interpretation of religion that portrayed men as gods, which they would likely have considered as degenerate as the city they conquered. Arianism was anathema to the Nicene Creed which had dominated most of the European Christian scene by 410AD when Alaric took Rome, and it (Arianism) was considered representative of the conquering Visigothic and Vandal elites, and probably also the old Pagan ‘barbarian’ ways which typically painted gods as greater and more potent forces than the corrupt mankind now dominated by Christian hierarchs. Christianity tended to view the world as fundamentally corrupt and damned and the 4th and 5th centuries certainly had more than their fair share of chaos to support this point of view, including serious disease epidemics, natural disasters and political and social upheaval. Still, Arian-styled christianity survived into the 7th century until it was gradually replaced by Nicene christianity or the violent conquest of Islam.