I came to my study of Christianity relatively late in life, shortly after I graduated college in my mid 20s. Before that time I was, at various points, atheistic (no god), agnostic (prove it), or deist (yeah, ok, God, but boy are His religions f'd up or what?) So for the vast majority of my life up to that point I had no real conception of just how deeply ingrained Christianity is on western societies, not just in America but everywhere considered "western". Most shocking of all to me was the discovery that Christianity in no small part created the secular and scientific society I loved and my "evangelical" associates hated. I had discovered that the belief system whose most vocal adherents literally made my toes curl in their ignorance was actually what made my way of life possible. How did that happen?
By melding the philosophical practicality of the Greeks with the organizational skill of the Romans, the early Christians created a powerful system to allow people to reason their way to faith. The works of men like Clement, Justin Martyr, Irenaeus, Origen, Tertullian and others instilled a tradition of logical criticism heretofore the exclusive pervue of the Grecian Jewish communities like that in Alexandria.
Of equal importance was Christianity's emphasis (again, copied from earlier Jewish communities) on monasticism. When the tides of Germanic and Nordic tribesmen finally overwhelmed the battlements of Europe and washed away the crumbling supports of the classic western world, the monasteries remained like rocks on a storm-swept beach. They remained not just as repositories for books that would otherwise be used to wipe the backside of a nose-picking Viking, but also as islands preserving the tradition of men (and, far too infrequently, women) dedicating their lives to learning for its own sake, indeed for the sake of their eternal soul.
European thought seemed to take a nosedive into the "dark ages" not because of a disdain for knowledge in and of itself, but because the instability of the countryside made it too dangerous to travel outside the walls of a monastery. Even when it was safe to travel there really wasn't anywhere to go. Largely rural even at the height of Roman power, Western Europe simply didn't have libraries on the scale of Alexandria or Antioch. Certainly the Muslims, who simply had the dumb luck of invading the most ancient and literate section of the planet west of the Himalayas, were in no hurry to share the hoards of knowledge they'd inherited, stolen, from the Infidel.
So the engine of Christian thought was forced to sit idle not from a breakdown of its parts, but from a lack of fuel to fire the boiler. It would take most of eight centuries for that fuel to be found, rediscovered, as crusaders brought back crates of books from both Spain and the holy land, and bilingual Jews made themselves available for their translation. The tank was filled, the parts were cleaned and oiled. It would only take someone turning the key to start the machine wheezing and chuffing back into motion.
That someone would be Thomas Aquinas, a brilliant thirteenth century thinker who set about harmonizing the spiritual world of developed medieval Christianity with the hard-nosed philosophy of the "rediscovered ancients". He did so with such insight that some of his arguments are still used today, eight centuries later. However, by even making the attempt he, and hundreds, thousands, of his monastic compatriots set a powerful precedent... Christianity would forever after be seen as a religion that both invited and paid attention to criticism not just from theological grounds, but from more secular "philosophical" ones.
Less than 75 years later the Death came and changed everything. By culling perhaps as much as one third to one half of Europe's population, the great plagues of the fourteenth century transformed nearly every aspect of European culture. The scarcity of labor forced a reliance on technology, which in turn created a practical market for the exchange of ideas that worked, not through the esoteric assertion of a monastic propeller-head, but through the school of hard-knock reality.
It was at this point that the engine lit by Aquinas was routed onto a side rail that took both its passengers and its purported engineers down the track to our modern world. The man who pulled that switch was named Galileo Galilee.
A brilliant, practical man with a tendency to speak the truth as it was proven instead of as it was given, Galileo was at first actually supported by the gigantic enveloping power that the Christian Church had become. Were it not for the movement founded by a truely meddlesome and hard-headed monk and the utter intransigence of a woman who refused to recognize she had no business ruling a country, let alone a church, Galileo's teachings would probably have been embraced outright.
Of course, it didn't work out that way, but through a series of technological and political coincidences, it didn't need to. The development of the printing press allowed Galileo's theories, and more importantly his techniques, to be spread literally faster than they could be burned. The rise of Protestantism allowed the nascent practicality of science to survive not because of any innate value, but because anything the pope hated was by definition something of value.
The fact that any nation that utilized the discoveries of these scientists almost automatically became a military and economic power was not lost on anyone paying attention. If that meant ignoring the growing number of increasingly uncomfortable theological questions their research was rapidly uncovering, well, as long as it meant our cannons blew the heads off of those who chose not to ignore them better and faster that was just fine.
Eventually though, the discoveries were so obvious, so powerful, and so revolutionary they could not be ignored. Science was proving that at nearly every point the Bible touched the natural world, it was getting it wrong. The child of reason, so carefully nurtured at the very heart of the religion that protected it for so long, had returned unrecognizable, seemingly intent on consuming the parent.
At this point, occurring roughly everywhere around the late nineteenth century, western civilization suffered a sort of nervous breakdown. Faith, still a core requirement for a well-rounded human being, became far harder to realize in a world where one could not relax comfortably in the warm pages of the inerrant book of one's ancestors. It suddenly had to be found through serious inquiry, long and hard quests for both internal and external knowledge, commitments people from western cultures many times simply found too hard or too frightening or just too much work to accomplish.
Two avenues were chosen, neither worked very well. Europe slid into a cold steel hell of nihilism, fascism, and communism, ultimately resulting in millions of its own citizens murdered in mechanized meat grinders so efficient we simply have no clue as to exactly how many were shoved in. The United States suffered a flat failure of nerve, with large sections of its society choosing to ignore and deny and fight any knowledge, any fact, that might upset the grand illusion that allowed them to accept the results of knowledge while repudiating its implications. The result was a citizenry often breathtakingly ignorant of the workings of the modern world, coming all too close in word and deed to the amber-frozen medieval Muslim fanatics they ridiculed from their own pulpits.
It would be tempting to think this leaves us at a crossroads today, but this is merely the narcissistic conceit of a culture still unable to come to terms with the universal truths of morality and mortality. We are instead still barreling across this dark and dangerous plane, riding an engine going so fast it broke the sound barrier long ago. It is badly dinged and worn in spots, and burns the unwary who touch it in the wrong places or at the wrong times. But its lights have guided us forward, steered us clear of the abyss of fanatacism and the cliff face of nihilism, even if it occasionally teetered or banged into each, hurling the willfully ignorant into one or the other at each turn.
And painted on its side, covered with decorations from a billion hands, intertwined with the symbols of a million beliefs and a thousand formulas, defining the debates even of those who utterly repudiate it, is the unmistakable symbol of the cross.