Christian writers, before and after Constantine, almost without exception, and in spite of the persecution of Christianity by Roman authorities, considered Roman universalism as a providential historical fact, which made possible the spreading of the Gospel on the “inhabited earth.”
Imperial Unity and Christian Divisions: The Church AD 450 – 680, John Meyendorff
The Roman Empire comprised much diversity in terms of peoples and languages, while at the same time providing for a commonality that facilitated the spread of valuable new ideas and philosophies – in our case, Christianity.
The empire spread from all of Europe to the West of the Rhine and the South of the Danube, also to include Britain, Spain, North Africa, Egypt, and the Middle East. This was an empire that did not suppress local cultures, languages and religions. Instead, it imposed a single administrative and legal structure.
Latin was used predominantly for administrative and legal procedures, while Greek was preferred by intellectuals in most urban setting, both in the East and in the West.
We see one effect of this spread of empire, very early on: