Christianity in the roman empire.

[Jona Lendering]

Am I correct in thinking that It is impossible to tell exactly when the roman empire became majority christian?

That is certainly correct, but I think that the reigns of the co-emperors Valentinian I and Valens (363-378) marks the final breakthrough. Constantine had protected and, when he conquered the eastern half of the Empire, used Christianity; according to his greatest fan, Eusebius, he was even baptized (no other evidence, though).

His sons were certainly Christians, and if you wanted to make a career, showing respect to Christianity was important; what you believed at home, though, was another matter.

Christianity did not really suffer from the persecution by Julian the Apostate (if there was a persecution; evidence is not so strong, I've been told).

During the reign of Valentinian and Valens, it became clear that the new religion was to stay. I think the return ot Christianity after Julian was the decisive moment.

Please take note of one question: to what religion did people convert? The main tenets of Christianity (as summarized in the Creed) were not established until the Council of Constantinople in 381 or so. During the reigns of all emperors mentioned above, conversion was easy, because there was no real consensus about what Christianity was about.

This started to change in the 380s, when the Creed was finally established and the Church was sufficiently strong to allow bishops to humiliate emperors: Martin of Tours speaking out against Magnus Maximus, and Ambrose insisting on Valentinian II and Theodosius I doing penance. In 392, Paganism was outlawed.