Religious Concept of Linear History and Interpretation of Europe's Conversion to Christianity

Lots of historians have tried to describe how and why the pagan people of Europe converted to Christianity in the early middle ages. I think the question is generally framed in Christian Linear History terms, which views the arrival of the messiah on Earth as a epoch making event where everything changed.

A more worldly interpretation is that Christianity was political useful for would be Empire builders. The tribal, traditional religions of local people was supplanted with a new tradition. We tend to think of Christianity in its contemporary role, confined almost totally to the realm of the spiritual. For the Europeans, religion was tied into every aspect of life.

The confrontation between the native Indians in the new United States was probably similar. Their whole way of life could not be harmonized with the way of life of the European settlers; a pastoral lifestyle, for example, can't really coexist (easily) with a farming lifestyle based on property, contracts, laws, and debts. It seems pretty likely that the tribal lives of European people couldn't coexist with the attempts to create kingdoms in the early middle ages, either.