Religion persists at the center of world concerns. Sunni Muslims and Shiite Muslims battle in Iraq. Religious divisions fuel ethnic conflicts around the world. The European Union was recently riven over a proposal to appoint Rocco Buttiglione, an Italian who holds orthodox Catholic views on homosexuality, as its commissioner for justice, freedom and security. We've witnessed a US presidential election in which, according to the polls, moral issues - interpreted by some to mean "Christian values" - were at the top of voters' concerns, outweighing the economy, terrorism, and the war in Iraq.
All this is hard for a European, particularly a Northern European, to understand. The reason is that we're heirs to a highly singular history whose origins lie in more than a century of religious and political warfare between Catholics and Protestants that began with the Reformation in 1517 and the Treaty of Westphalia in 1648. The memory of those wars drove the intellectual and political history of Europe for more than 300 years, leading to the rise of science, the nation-state, the growing independence of universities, the de-sacralization of culture, and the retreat of religion from its former citadels of temporal power.
This secularization did not take place because people stopped believing in God. That, if anything, was a consequence, not a cause. It happened because men and women of goodwill lost faith in the ability of religious believers to live peaceably with one another. With Catholics and Protestants fighting each other across Europe, people began to search for another way. Could we, they asked, find a path of pursuing knowledge, or wealth, or power, while leaving our religious convictions at home? Thus began what the English poet and essayist Matthew Arnold called the "melancholy, long, withdrawing roar" of the retreating sea of faith.
The advance guard of the Enlightenment believed that where Europe led, the rest of the world would follow. Secularization, they believed, was inevitable and inexorable. It would be the fate of every civilization that attempted to come to terms with modernity. In this they were simply wrong.
The US, for example, chose an entirely different route - the First Amendment, with its separation of church and state. The result, as the French observer Alexis de Tocqueville saw as early as 1830, was that what religion lost in power, it gained in influence. It moved from state to society, from Congress to congregation, and from national to local affairs, where it exercised immense sway. The effect of "denationalizing" the church was to open up religious denominations to the bracing winds of competition, generating wave after wave of revivalism.
If, in Europe, modernity meant a retreat from religious passion, the American paradox is that such passion coexists with secular politics. But in other parts of the world there has been a third trajectory, in which religion has emerged as a mass protest against failed secular nationalisms of the kind that Gamal Abdel Nasser introduced in Egypt and Saddam Hussein in Iraq. There religion functions as a critique of modernity: mass poverty, widespread unemployment, political corruption, and human rights abuse.
In such environments, religion alone seems to speak the language of human dignity and hope, and until we understand this, we will utterly fail to comprehend the strength of reaction against regimes that sought to imitate the West.
Religion didn't die. It persists as humanity's oldest, noblest attempt to endow human life with meaning. Secularization turned out to be the exception, not the rule.
This leaves us all painfully ill-equipped to come to terms with some of the most intractable conflicts of the 21st century. Nothing is served by crude caricatures - the secular view of religion as irretrievably fanatical, or the religious view of secular culture as irredeemably decadent and effete.
The real question is whether we can make space for difference, for the one who is not like us. This has nothing to do with the truth or falsity of religion. The question has nothing to do with God, and everything to do with us.
• Jonathan Sacks is the chief rabbi of the United Hebrew Congregations of Great Britain and the Commonwealth. © Los Angeles Times.