Not that I am sentimental about the old pagan religions of Europe, although I think replacing a people's religion also destroys a lot of their culture...at least that's what happened here in North America...anyway, back to the point,
how much of that gradual conversion process you describe contained persecutions and killings that were not kept in the public record and wallpapered over by the Church authorities afterwards?
There are some notable cases where the Church did order wars of conversion of the last pagan holdouts. For example, check out the Wikipedia article on the Teutonic Knights, and
scroll down to the "Against Lithuania" subheading, and check out the long, bloody war of conquest the Pope ordered against one of the last pagan holdouts in Europe who refused conversion and allegiance to the Vatican. I think the history of Christianity in Europe, if it can be distilled, is one of a messianic religion becoming extremely popular among lower classes in the Roman Empire, chosen by an emperor who saw this new religion as a possible unifying force to keep the Empire together, and then enforcing orthodoxy among its scattered churches, and finally, when it had reached almost absolute power, forcing neighbouring nations to convert or be put to the sword by their knights. So, Christendom became extremely oppressive and despotic when it had the power to do so, and that's how secular movements got started to clip their wings!
And modern Europeans should be extremely vigilant against this Pope and his minions who seek to take back power over the people that they have mostly lost...except for Poland it seems!