i've actually made this point over and over again: the idea that the culture of northern europe (the culture of the germanic, celtic, baltic and slavic nations, as well as the historically iranian cultures of europe (alans, scythians, sarmatians, etc)) is fundamentally christian, or erected on a christian edifice, is a colonial lie presented by the christian church. it's complete bullshit.
that is a claim that has more merit when applied to the southern parts of europe, and actually even has more merit when applied to the middle east and northern africa. egyptian culture is more fundamentally christian in origin than swedish or english culture is or ever will be.
the historical truth is that this area was brutally invaded and colonized first by romans and second by christians, who attempted to eradicate the indigenous culture and people and replace it with their own. what the romans did to the celts would qualify as outright genocide by modern standards. but, the barbarian north then spent centuries, and in some cases millennia, fighting back against these roman and christian invaders.
when these germanic tribes moved south to destroy rome, they were in a very large part moving to destroy christianity, and this is as true of the goths as it was of the last viking raids into france and england. they always targeted the churches, above all else; they would plunder and rape, yes, but burning down the church and the monasteries was always the central prerogative of the raids. and, there's a serious body of evidence that interprets this as self-defense, from a reaction to the romans slaughtering celts from britain to switzerland to an allied, pan-germanic response to charlemagne's attempt to eliminate the saxons.
beyond that, this idea of there being a western empire in the first place is questionable. the romans did not build the east, they inherited it; it was built mostly by the persians, and then renovated by the greeks. the romans literally even bought large swaths of it. so, with the exception of the pesky jews, it was less prone to nationalist uprisings, because they all saw themselves as a part of the same culture. when the east did revolt, it revolted together. in the west, there were constant revolts from the time of caesar. at almost no time in history was there actually centralized roman control over hispania, gaul, britannia and germania all at the same time. there were, rather, constant uprisings of celtic tribes, german tribes, various confederations of tribes, roman pretenders and anybody else that could take control of an army long enough to cause a ruckus. in that sense, the very western roman empire itself - the supposed basis of western "civilization" - is largely a mythological construct. the peoples of northwestern europe saw the romans not as bringers of civilization, but as cruel overlords, oppressors and destroyers, and they never stopped fighting them for their freedom, which they eventually won by burning down the cities of their oppressors.
over time, the celts were assimilated nearly entirely and the germans slowly adopted aspects of christianity, but to suggest that christianity was the basis of the culture is backwards. the legal systems in these countries, especially in england, are fundamentally germanic, and then borrowed aspects from roman christianity, rather than the other way around. our religious traditions are fundamentally germanic, even if they have a christian gloss over them. our cultural traditions are individualistic and libertarian, not hegemonic or hierarchical. and, we've struggled from the start to see the logic in treating women as inferior livestock. we are not christians, we are barbarians.
when the dust of the last viking attempts to destroy christianity settles, what is left is a feudal society dominated by warlords that use christianity as a tool to manipulate their conquered peoples. in the end, the barbarian overlords found christianity too useful to dismantle altogether. but, it was never a driving force for any meaningful decision made by anybody. and, the scribes were still reading their latin texts, insofar as they could find them.
so, people ask the question of when it was that christianity began to unravel in the northwest. was it recently, as per nietzsche? was it in the age of enlightenment? the renaissance? the reformation? the black death? while these all mark turning points of victory in the struggle against the church, i might argue that the question is illusory: these areas were never fully romanized, never fully christianized, but have rather spent the entirety of history fighting hard to maintain their identity in strict and brutal opposition to the dominance of the encroaching church.
that is our history, as northern europeans: we are not products of christianity, but victims of it.