Sky Television subscribers can, if they wish, tune to a channel called TBN.

The Trinity Broadcasting Network originated in the US but its recently launched European offshoot targets English speakers across the continent and in the Middle East. Colonialist in tone, it parades Christian Arabs talking about their conversion from Islam. Prayers (in English and Arabic) for further conversions are greeted by applause from an off-screen congregation. Some of its programmes encourage viewers to phone in. Its president, Paul Crouch, has a succinct way with anyone who challenges his Bible-based teaching. “God’s goin’ to shoot you if I don’t... Don’t even call me if you want to argue... Get out of my life! I don’t want to talk to you... I don’t want to see your ugly face!”

Since the 1960s, Christian television networks across the US (and now in Britain) have provided a platform for preachers expounding what they see as the fundamentals of their faith - which may or may not include Christian charity. Indeed, such preachers can be quite strong on hate. This is the message of Randall Terry, founder of the American anti-abortion movement:

“I want you to just let a wave of intolerance wash over you. I want you to let a wave of hatred wash over you. Yes, hate is good... Our goal is a Christian nation. We have a biblical duty, we are called by God, to conquer this country.” Yet another speaker announced that, in order to win over the nation, “The sword as well as the pen must be used”.

On September 11, 2001, Muslim fundamentalists took that dictum to its extreme. It is now difficult to open a newspaper without encountering the words “fundamentalism” or “fundamentalist”. Frequently these words are used carelessly or casually - so much so that in this country, one paper, the Church Times has placed a moratorium on its use, usually preferring a term such as “extremist”. In fact, dictionary definitions are precise: “Belief in the literal truth of the Bible; adherence to strictly orthodox religions or other, eg political, doctrines” (Chambers Dictionary); and “Form of Protestant Christianity which upholds belief in the strict and literal interpretation of the Bible” (New Oxford Dictionary). However, the latter definition is extended: “Strict maintenance of ancient or fundamental doctrines of any religion, notably Islam.”

Dictionary definitions are, very properly, non-judgmental. In real life, it is much harder to be impartial. Those who hold fundamentalist beliefs have strong convictions, unshakeable faith and (often) great courage. They maintain what they see as historical truths and refuse to be swayed by the changing fashions of a decadent, secular world. They also have a confidence, stemming from their convictions. Liberals believe that fundamentalists promote ignorance and intolerance and that they insist on a doctrinal conformity resulting in a lack of love and compassion. At its worst, liberals argue, fundamentalism leads to an intellectual and physical terrorism that will plunge us into a new Dark Age. They cite news stories as disparate as the debate in American and British churches over gay clergy and attacks on abortion clinics, along with such atrocities as the Bali and Madrid bombings. Liberals can also point to a side effect: the adoption of religious language (“evil”, “crusade”) by political leaders. Indeed, the liberals do appear to have reason, justice and evidence on their side. But they also face a dilemma. Should they extend their tolerance to fundamentalists - or must liberals adopt an almost fundamentalist stance and join a political “war on terrorism”?

Fundamentalism is not a new concept. The term was coined in 1920 by Curtis Lee Laws, an American journalist. He used it to describe an “antimodern” Protestant movement which preached the literal truth of the Bible and the sinfulness of humankind; a movement which described these (and other tenets) as the “fundamentals” of faith. While modern Christian fundamentalism may have its roots in such American movements, its origins date back to the mid-18th century.

At that time, what were then known as the American colonies experienced a religious revival, during which numbers of highly effective if melodramatic preachers successfully frightened many people into becoming devout Christians by delivering powerful sermons describing the horrors of hell fire. This movement later became known as the First Great Awakening. A Second Great Awakening took place in the early years of the following century. This time, preachers offered salvation to those who “made a new start” or were prepared to be “born again”. The next comparable (American) religious fashion was the “millenarian movement”, its followers emphasising the literal truth of every word of the Bible and predicting the imminent Second Coming of Jesus. In 1902, millenarians were joined by other literalists to form the American Bible League, the movement that was to be described by Curtis Lee Laws as “fundamentalist”.

It was a science teacher, John T Scopes, who next made the movement newsworthy. During the 1920s, fundamentalists had been campaigning against the teaching in schools of Charles Darwin’s theory of evolution and the principle of natural selection (since they believed such theories contradicted biblical stories in Genesis). Their campaign led to laws being passed in 11 states, making it illegal to teach “Darwinism” in state schools. Scopes, who taught at a school in Dayton in Tennesee, broke the law. He was prosecuted, found guilty and fined $100 - and his trial caused nationwide ridicule of fundamentalism. Even so, the law in Tennessee was not revoked until 1967.

Just as Darwinism was perceived as a threat to traditional faith, so too was communism. The 1950s saw the emergence of a new generation of evangelical and fundamentalist preachers, the most well-known being Billy Graham. Thirty years on, his successors were the televangelists such as Oral Roberts, Jim Bakker (whose followers were only a little shaken by revelations of his adultery and financial fraud) and Jerry Falwell, leader of a coalition opposed to social change, which became known as the Moral Majority.

Falwell’s response to the attack on the World Trade Centre in New York is not unrepresentative of his views: “The abortionists have got to bear some burden for this because God will not be mocked. And when we destroy 40 million little innocent babies, we make God mad. I really believe that the pagans, and the abortionists and the feminists and the gays and the lesbians... all of them who have tried to secularise America, I point the finger in their face and say - you helped this happen.”

A bleak irony lies in the fact that the tragedy was caused by fundamentalists even more fervent than Jerry Falwell. As with Christian fundamentalism, it is necessary to look back in history to discover the roots of today’s Muslim fundamentalists (or Islamists). For 800 years, a tenet of Islam was the pursuit of knowledge, or ilm. Muslims led the world in science, medicine and mathematics. They built universities and hospitals, and developed algebra, trigonometry, spherical geometry and optics. They invented the test-tube and manufactured paper and irrigation tools.

But, from the period of the Crusades onwards, Muslim countries were colonised by western empires. The downfall of the Ottoman Empire left the Muslim world with no overall leader. In tandem with this process, ilm, which can be translated as both acquired and revealed knowledge, came to be more narrowly interpreted as the latter. The interpretation of the holy book, the Qur’an, became the preserve of religious leaders rather than questioning students. The result was a narrowing of the faith, a kind of introversion. It became acceptable, even the norm, to read the Qur’an in literal terms and to enforce its legal rulings (the shari’ah) harshly in some Muslim countries and regions such as Nigeria, the Sudan and the newly independent republic of Chechnya -sometimes resulting in severe penalties for adultery, theft and immodesty.

In such an atmosphere, continuing anger over western imperialism (and the exploitation of Middle Eastern oil) has bred deep anger. The response has been the rise of a modern fundamentalism: a desire to strengthen Islam by insisting on the “purest” form of the religion. In practice, Islamist fundamentalism varies from country to country. In Iran, women may drive cars and (with their husband’s permission) go out to work. Under the fundamentalist Taleban regime in Afghanistan, women did not even have the right to basic education. The aims of Islamists also vary. For example, the aim of the Palestine resistance movement, Hamas, is simply to create an Islamic republic of Palestine. Al-Quaeda, under Osama bin Laden, has expressed a desire for one worldwide Islamic empire under central control.

Their different ambitions may be political but the movements are underpinned by support from religious fundamentalists.

Here we must return to the classic liberal dilemma. Where should liberals draw the line? Imagine a suburban vicar, standing in his or her Sunday pulpit, surveying a traditional middle-class congregation. In an attempt to arouse their faith and commitment, the preacher poses a favourite rhetorical question. “Suppose you lived in a country where it was illegal to be Christian. Would there be enough evidence to convict you?” The intentions are understandable -commitment, to the believer, is laudable.

But what if commitment becomes so complete, believers are prepared to lay down their lives for their faith - as suicide bombers?

It has been said there are elements common to all types of fundamentalism that are unacceptable to the majority. Fundamentalism is usually patriarchal and often misogynist. It has an unhealthy preoccupation with (and fear of) sexuality. It can be hypocritical. For example, Christian fundamentalists once quoted the Bible to preserve slavery - a point they rarely make today. Similarly, many have adjusted their convictions to accept the remarriage of divorced people (despite its condemnation by Christ), possibly because too many fundamentalists are themselves in this situation. With minorities (such as gays and lesbians), it is different - few of them are likely to be fundamentalists.

Fundamentalist teachings (such as those of some televangelists) sometimes take the form of verbal assault. They can also all too easily breed physical violence. Nor does fundamentalism tolerate diversity. Such tolerance is vital to peace and security, whether it is on a city centre street, within a nation state or on the wider world stage. Perhaps even more importantly (and unlike the founders of Christianity and Islam), it blocks progress and the search for new truths and ideas.

In Europe, it is tempting to be complacent. This continent, after all, has seen less overt fundamentalism than America’s Bible Belt or Iran. But that is not to say that that it is absent from British streets - and schools.

Earlier this year, a documentary on the BBC’s black music digital station 1Xtra took us into some of the East London and Birmingham meeting places of young Muslims and revealed how many are taking increasing pride in a traditionalist heritage and embracing a strict morality. To be cool and trendy, a young Muslim male now needs to sport a hat, a beard and a shirt that covers his knees. The strictest among them reject television, western music and a society they see as morally lax. However, one 16-year-old boy in Whitechapel was also completely willing to give up his life for God: “My duty as a Muslim is to fight.”

More than one commentator has suggested that, since it is impossible to convert fundamentalists (their creed tells them they are without error), the only way to counteract fundamentalism is through the development of critical thinking skills within secular schools. One such American commentator, Scott Bidstrup, suggests that the US has proved a fertile breeding ground for fundamentalism because, in his words, “the public education system has collapsed” - and because there is inadequate, objective teaching about the world faiths.

For Bidstrup, the answer is to teach critical thinking skills and logic; to help pupils to gather evidence and to make deductions from that evidence, rather than accepting given conclusions and then seeking biblical or Qur’anic evidence. This is particularly difficult to achieve in Muslim countries, especially those where shari’ah law holds sway, but the increasing numbers of Muslim modernists need support in their attempts to broaden ilm.

As well as such educational programmes, we might pursue what the British Chief Rabbi, Dr Jonathan Sacks, has termed “counter-fundamentalism”. This ideal he defines as belief (rooted in the sacred texts) in the sanctity of human life and in human dignity - qualified by “the imperative of peace” and justice tempered by compassion.

Win or lose?

Fundamentalists win:

* By defining a precise and literal way that holy scriptures may be interpreted

* By directing their attacks at a particular group or activity

* By claiming they have long been excluded from leadership positions

* By insisting on their loyalty to historic truth

* By developing communication and even media skills

* By embracing any right-wing political drift and also the disaffected

* By being prepared to use violence to further their ends.

Liberals lose:

* Because of their lack of unity and sense of purpose

* Because they do not formulate a simple manifesto

* Because of a reluctance to enforce their views on others

* Because of their intrinsic moderation

* Because they waste time attempting to convert their opponents

* Because of a dislike of “getting involved”

* Because of a reluctance to use violence to further their ends.