Mithraism courted the favour of Roman paganism and combined monotheism with polytheism, while Christianity was uncompromising.
The question as to the influence of Neoplatonism on the development of Christianity is not easily answered, because it is scarcely possible to get a complete view of their mutual relations.
The members of the Church were somewhat shocked at the reception of a Gentile: their view apparently was that the only road to Christianity was through Judaism.
The historical relation of Mani to Christianity is then as follows.
When Christianity became powerful the heathen philosophers evaded its satire by making more and more use of the allegorical and non-natural system of explanation.
He observes with truth that Natural Theology, if you remove from it the idea of subordination to Christianity as (claiming to be) a special revelation, tends to pass into a philosophy of religion.
This Arian form of Christianity was imparted by Ulfilas and his disciples to most of the tribes of the Gothic stock, and persisted among them, in spite of persecution, for two centuries.
It was also about this same period that the grave scandal of the Chinese and Malabar rites began to attract attention in Europe, and to make thinking men ask seriously whether the Jesuit missionaries in those parts taught anything which could fairly be called Christianity at all.
He believed that Christianity had existed from all eternity, and that the Greeks and Romans, sharing in God's truth, would share also in the celestial joys.
In Constantinople he seems to have early won the notice of Justinian, one of the main objects of whose policy was the consolidation of Eastern Christianity as a bulwark against the heathen power of Persia.