Why all this establishment?

In almost every confrontation between an organized religion and an 'indigenous' one, the organized one has succeeded in converting the natives - or enough of them that the old system is fatally undone. This happened again and again, in vastly different times and places:

• The Turkic peoples of Central Asia took on Islam and moved away from their traditional shamanism
• The various African religions and tribal idea systems were absorbed, broadly, into either Christianity or Islam
• The Americas were Christianized over hundreds of years
• Europe, after the fall of Rome, was Christianized out of scattered pagan, polytheistic, druidic and shamanistic faiths
• East Asia was thoroughly taken over by a combination of Buddhist and Confucianist ideas which replaced ancestor worship, Korean shamanism, scattered Chinese paganisms, Indochinese idol worship

Each time, a 'codified' faith entered the region of an uncodified one. These 'loose' religions may have been at a disadvantage because they had no book to refer back to, or because they were simply never examined with academic rigor. Yet Islam spread among the illiterate Turkics, so the Quran was not such an advantage. And Greco-Roman paganism had hundreds of volumes dedicated to its study, but was not spared from the overwhelming wave of Christianity. It seems that the codified religions win out, given enough time. As we can see today, the very last vestiges of African Traditional Religion are being swept out - now all ATR is rolled up into Christian and sometimes Islamic faith. Fewer and fewer people are identifying themselves as practitioners of only ATR. I believe there is only one African country where the largest religious group identifies as only ATR, and they are not an absolute majority - just larger than either Muslim or Christian populations.

But does it have to be this way, historically? The evidence - which I have not come up with a theory to explain - seems to indicate yes. Of course, you can explain away any one case: the Americas were Christianized because the Europeans had the technology and the germs to prune away rebellious populations, etc. But you cannot explain away all the cases.

Do uncodified religions ever survive, then? Yes they exist in the US, but anyone who thinks the Native American Church (a native/Christian hybrid anyway) is a powerful movement is in need of medication. But uncodified religions do survive. It is my understanding (knowing very little about either) that both Indian Hinduism and Japanese Shinto crystallized out of various native paganisms. So, by that count, nearly one billion people do identify as some kind of aboriginal religious group.

I recently read a book called The Barbarian Conversion, which detailed the Christianizing of Europe after the death of Rome. Some stories in it are familiar to anyone who's taken a course in Medieval history - the conversion of the Franks, the various Germanic conversions, the eventual Scandinavian conversion. But there was one section that proved most interesting of all: Eastern Europe.

The book spent some time on the East, past the Germanic tribes where no intro course dares to go. In the area of Poland-Balkans-Baltic-Slavic people there was a tremendous diversity of religion. And somewhere in there was a group called the Wends, who are possibly the greatest religious what-if of Medieval Europe. They followed a relatively familiar polytheistic faith, similar to the Norse or Germanic tribes. Various gods for various jobs, with a head god who was most powerful. The Wends (who didn't call themselves that) held out against Christianity for quite some time, until a few military losses and royal deaths but Christians and Christian-sympathizers into power. Wendish paganism lost all real power in a short time after this confluence of events. What is so important is that just before this mess happened, the Wends were being politically united more like Western European proto-states, and their religion was being codified.

It seems that some anti-Christian Wends had thought very seriously about their faith and had done a lot of the work needed to call something codified. We don't know much about it, but organized Wendish paganism may have been a short time away from presenting a serious religious challenge to Christianity. The Wends were trapped between Eastern Orthodox Slavs and Catholic Germanics, so even if they'd managed to fend off the Christians their organized paganism (the first to my knowledge in Europe) wouldn't have been able to expand very far. But how different might Europe's history have been if there had been a pocket of non-Christian, even anti-Christian believers somewhere in the region between Poland and Greece?