It's a common, but misconceived, idea that Western people have grown disillusioned with religion because of religious wars in the distant or - in the almost unique case of Northern Ireland - recent past.
People on the Left have taken this view with a bit more consistency than those on the Right.
Think of John Lennon's song Imagine. He saw world peace and unification in the abolition of what he considered as all causes of division and conflict: religion, class, nation.
Lennon was, to put it in euphemistically-correct language, "cognitively challenged", but at least one can't deny his consistency and even-handedness in spreading the blame for war potential among different causative factors.
On the Right, instead, we have activists who condemn religion for provoking wars while at the same time strenuously supporting the value of nationhood.
Let's look at this as scientifically and empirically as we can.
Vast numbers of people have been killed in wars fought along class lines or for socialism, or proclaimed as such, and in their aftermaths: French Revolution, Russian Revolution, China, the spread of communism to Eastern Europe, Spanish Civil War, Vietnam, and these are only the main ones. Lennon's idea of the pacifying effect of the abolition of classes was not very far-sighted.
Many have also been killed in self-declared national wars: European wars, American Revolution, the Two World Wars, wars against colonial powers and so on.
And many have been killed in Christian religious wars; in fact there is an overlapping of several national and religious wars in Europe.
The reasons why I limit myself to Christianity are two: it's always been the religion of the West, and - not coincidentally - it's the only religion that can survive rational examination.
Writers like the New Atheists have had some influence in setting the current debate in terms of simply "religion", as if we could treat all religions in the same way.
But think if we did that with science.
After all, science includes many different theories. Some of them, like Ptolemy's geocentrism postulating the earth at the centre of the universe, have now been rejected. And yet Ptolemaic astronomy is a scientific theory, both in the historic sense that it was for centuries accepted by the scientific community, and because it used the best scientific methodology available at the time.
In the same way as, when we talk about science, we make distinctions between theories - invalid ones like geocentrism or Copernicus' circular orbits and currently valid ones like relativity and quantum physics -, so we should do when the subject is religion and distinguish among greatly different doctrines.
Religions other than Christianity are primitive and constraining: Judaism with its excessive, indeed obsessive, emphasis on a great number of laws and rituals; Islam ordering the slaughter of all infidels to establish a utopian paradise on earth; Hinduism with its plethora of deities representing contradictory values; Buddhism with its withdrawal from the world.
Christianity has represented an immense liberation and step forward for mankind.
I am not saying that attachment to one's nation is a bad thing; far from it. I think that - if it doesn't trascend into fanaticism - is a value to cherish.
Many good things can become bad if fanatically supported. That is true of defence of nationalism as well as blind defence of science of the kind that Richard Dawkins has accustomed us to.
I just question the consistency of someone who adduces religious wars as the reason to reject Christianity but doesn't consider national wars as a reason to reject nationalism, despite the fact that violence and massacres were caused by both.
Indeed, the first century after the triumph of "secularism", the 20th century, has seen some of the bloodiest conflicts and genocidal wars in history.
The reality is that the progressive abandonment of Christianity in its home, the West, in particular in Europe, has not been caused by a reaction to religious wars. It has not been a spontaneous process in the consciences of native people, but the effect of instigation and propaganda by few, by elites with their own ideological agendas and alien interests, often damaging to the indigenous population: communists, atheists and ethnic elites, frequently the same people.
"Bundesarchiv Bild 175-14676, Leipzig, Reichsgericht, russischer Panzer" by Bundesarchiv, B 285 Bild-14676 / Unknown / CC-BY-SA 3.0. Licensed under CC BY-SA 3.0 de via Wikimedia Commons.