Actually, the dominant Christians were in Egypt, at Alexandria as well as in Carthage, North Africa, not in Rome.
While deliberations were going in the early centuries regarding matters such as the Biblical Canon, the Church of Rome was a minor bystander. Other major players came from the Eastern Mediterranean.
When the vicious internal Christian wars of the 4th and 5th centuries decimated the North African Christianity, it moved northwards, becoming a European religion. One should compare the nature of the African religion as is still practised in Ethiopia - along with its Canon.
Doctrinal decisions, such as on the nature of God, the Trinity, and so on, were not made by the Church of Rome. These determinations were forced upon the communities by the edicts of Roman Emperors, with Theodosius in particular.
The European style of Christianity, in which the Pope and his henchmen ruled with an iron fist, shed its Jewish origins, to the point where images of Jesus are of a pale skinned European. A clear example of its anti Semitic position.
Religions speak of "Jesus coming back" to create tension, expectation and to hold the sheep within its grasp.
Doug