I agree Helena, Constantine’s mother, played an important role in the establishment of the Roman church and hence modern beliefs, especially in setting the RC trend for relic worship.
The key to the establishment of Christianity was not Constantine’s interest in faith, religion or morality, for an emperor perforce had neither faith nor much in the way of moral scruples to start with, nor was it the doctrinal correctness of Helena’s brand of the Jesus cult which appealed to him but instead it was his banal superstition in trusting that her religion would bring him luck... in the form of military success.
It is essential to recognise that religion for the Romans and Greeks had been one of obligation to the gods, piety was something demonstrated by public and domestic observance of the rituals, it was not a matter of faith or morality. Superstition played an important routine part of the lives of the ancients whatever status they had.
Constantine had the morality of a
hungry tiger; he may have had a soft spot for mum but had his son murdered and
his wife forced into a bath of boiling water. As far as religion went, he
despaired at the bishops who obdurately wrangled over 'true' doctrine, a concept apparently alien to the emperor. Constantine saw
them only as an impediment to his political ambitions for an unchallenged faction-free
universal state religion and wanted to bang their heads together. Only then would it become an instrument for unity and
consequently for the strengthening of his imperial hand. (qv
DG Kousoulas, The Life and Times of
Constantine the Great 2007)
This ideal of pure worship in the mother church had been achieved through a deliberate syncretism or fusing of all pagan belief into the catholic or universal faith and subsequent enforcement made it a Roman’s obligation to worship in the state prescribed manner and simultaneously it denied any rights to the former religious groups which included the destruction of all available texts relating to them. Catholic orthodoxy ruled!
The origins of modern Christianity might therefore be (rather too briefly) summarised as: the syncretizing of all beliefs, pagan and mystical, by imperial power, promoting it as the state religious cult and then proscribing all others... and all of this done for the sake of political power, superstition and family sentiment.