Stories? Entire nations converted due to these events. I have serious doubts that an entire nation converted to Christianity by hearing false stories. Also if the gods Odin, Thor, Sil, etc. really existed then Christianity would have been stopped in its tracks. If they were real, Charlemange would not have won the last battle against the Lombards. We would all be speaking German, Old Swedish and other Northern European tongues. The Roman Empire would not have lasted over 1000 years (including the continuation of the Eastern Roman Empire). The pagans of the day would have overran the Christian parts of Europe. So tell me this if the pagan gods are real then how is it that Christianity triumphed over paganism so many times long ago? Or did these events never occur? God speed.
First, I would point out that we might ask the same question concerning Allah and Byzantium. Or Judea. Or Antioch.
Also, we all speak (or at least type in) a northern tongue - English, which is a germanic language. Note that our days are named for Norse Gods in several cases - Tuesday for Tiw, Wednsday for Woden, Thursday for Thor, Friday for Frigg. Many of our month names are Pagan as well, though from the Latin.
Pagans don’t believe in omnipotence. There is no being that rules all the world, that controls the fall of the sparrow, that determines the destinies of nations. Human free will is, itself, an expression of the divine, and we make our own Fates, along with the influence of the Gods. So, when we look at the flow of the rulerships of nations and the religions they follow, we would look at the usual socio-political factors.
There’s no doubt that early Christianity had great vitality, and an attraction to a certain sort of seeker in the late classical world. By the time of the Nicean Council, about 50% of the population of the core cities of the empire would have been Christian - a remarkable growth for a movement that really became visible in about 100ce. The Roman soil had been tilled by the presence of Judean monotheist synagogues in Rome, over the previous century before Jesus.
The big turning point was when the empire, in its growing centralization, decided that there would be an ‘official’ religion of the empire, and took the gold and social position from the old hellenic temples.
There’s no doubt, as well, that hellenism was tired and rather used up. Oriental cults (of which judaism was one) had been popular in the empire for centuries, and the old hellenic gods were seen a either peotic tropes, or merely quaint. How do these things happen? Hard to say, but Pagans don’t assume that the forms of the divine are eternal - all form changes - ceasing and recurring according to need.
After Constantine there was a 1,000 year effort to completely destroy the old religions. The north converted gradually, with many remnants of old ways that never really left. The Lithuanian empire didn’t even start to convert until the 14th century, and the Old Gods began to return as soon as the renaissance loosened the grip of the church. While the political victory in the roman world was pretty complete, the Old Religions have never been far from european awareness, and are now returning in formal shapes.
It was really the protestants who came closest to destroying the Old Ways. The Church had co-existed with a lot of local survivals, and the church’s near-polytheistic calendar of saints with their images, symbols and customs was both a resplacement and a disguise for the Old Gods. When the prots came in, with their image-breaking and puritanical moralities, even the euro countryside was cleansed of its folklore, where possible. The Maypoles were cut down, and even the fiddles of the people broken. nasty business…
Monotheism is just one God away from atheism. The efforts of the prots to enforce a strict, imageless, abstract monotheism is one of the real sources of the so-called enlightenment’s dawning materialism. Pagans like a world filled with spirit, and with spirits, where the divine is always nearby, because some God is always nearby.
So, how did it happen? It happened because Christianity was in the right place at the right time, and won the political battle in Rome. It happened because Christians were willing to undertake campaigns of violence to enforce their religion - a thing that had seldom occurred to Pagans. It happened because Christians refused to do business with non-Christians, leading to merchant baptisms, etc.
When, in 100 years or so, there are Pagan temples in many American towns, we’ll have a different set of questions to ask…
Ian