Quaint are these arguments pinning all the woes of the Western world on religion, on Christianity. Typically, Christianity is blamed for any and all murders, genocides, etc. I find that systems void of any deity are quite effective at slaughtering people too, thus we had millions killed, murdered, exterminated under fascism/communism (and whatever "ism" Pol Pot ran).
In the Abolition of Man Lewis argues that there has always been a string of truth throughout civilization (citing there is only one civilization). He calls this the Tao and argues that it has always existed and keeps cropping up no matter what in whatever religious form. Kant's paradox points this out as he compares the mystery of the starry heavens to the mystery of the moral law within. We just can't escape it -- this need to do and be right, so, call it what you will, but Christianity is simply another form of it (no one ever said it was perfect).
Lewis goes on to note that, for the first time ever, the Tao is actually under attack and in jeopardy of being done away with -- that this is a unique event in history. This is exactly what happened the last century in Germany, the USSR and Cambodia -- Taoless (The Tao being a general concept of a supernatural force we must answer to) systems took over the minds of humanity (yes, even in Cambodia -- oddly). Now, people died, and, sure, people died under religions too, but the fact remains that, for the first time ever, people were killed, en mass, not for land, not for belief, not for any reason other than the fact that they no longer should exist on the planet. The Jewish Holocaust is the best example of this. It was killing, for the first time ever, with the goal of entirely eliminating a certain people from the planet. Say what you will, but all other wars and conflicts had another, primary, goal.
In short, Christianity may suck, religion may suck, but these have never produced the goal which a Taoless system has produced, nor has ever such a dismal concept been conceived in any religion.
Irreligious systems, Taoless systems (communism, fascism, etc.), surprisingly, have the same goals as religion. They simply don't want a god to be any part of the solution, but this causes the paradox of demanding the function of a heart without having a heart. We simply don't behave very well on our own without the thought that we will, eventually, answer to a higher force. It is the brain that feeds the stomach through the heart. We remove the organ and demand the function.... We castrate and then demand the gelding procreate -- it simply cannot happen. Or, Lewis puts it another way, "what makes a man sit in the trench through the 6th hour of bombardment for God and country?" which he answers, "what else can make a man sit through the 6th hour of bombardment but God and country?" (These quotes from memory). This leads into thought that along with religion comes concepts of country, nationhood, family, etc. One could argue that we are moving beyond these hindrances -- that the American Civil War marked the end of state-centeredness and into nationhood, or that the end of WWII marked the end of nationhood and into a global community. Indeed, perhaps we are moving beyond god, beyond the boundaries of answering to such a force, but without the heart -- without these pesky religions -- it is an ominous world looming wherein there is no great parent up there to whom we must answer, where Nietzsche's ubermensch will create his own world, in his own likeness and the final minorities who don't look like me must be removed as so much infestation.
I empathize with Voltaire who witnessed the horror of a flawed religion, a flawed Christianity. I empathize with Bultmann who attempted to save the embattled faith from itself, but at the end of the day Kant's "moral law within" cannot be escaped, nor can it be supplanted with a godless system based on what's best and what's best void of god, for what's best void of god is relative and what's relative is horrific and so the 20th century has taught us.... The removal of the Tao produced for humanity the mindset to eliminate his fellow man for the sake of elimination and the grand achievement of human effort produced the nuclear bomb. What will happen when the twain finally are joined?