Despite the efforts of the massive self-help industry and our confessional culture, there is no human transformation as profound as that of religious conversion. Nothing works quite like religion to create the new person. Sometimes, the convert suddenly acquires a new world view, a new identity, and for those who adopt Islam, even a new Arabic name. Conversion should raise as many questions about the convert's psychological state as it does about the theological reasons, but the former are usually subsumed in the new happiness.

Despite natural suspicions about conversion, human religious development is the history of men who rebelled against existing beliefs to create something new. Abraham, if he existed at all, left the security of his Semitic gods for an unknown future further west and his own exclusive tribal deity, Yahweh. Twelve centuries later, in Northern India, Gautama Siddhartha, the Buddha, rejected his aristocratic privileged position within Hinduism to seek his own salvation and lay the moral principles for millions in the far east.

Other great rebels followed, Christ in Palestine, Mohammad in Arabia, Luther in Germany and Nanak in N. India, the founder of Sikhism. Perhaps the most significant rebel in western history is Saint Paul, a strict Jewish lawyer, who went from persecuting the new Jewish-Christian sect to becoming its greatest champion by reaching out to non-Jews.

Conversion can also be an act of collective political and social defiance. Take for example, the mass conversion of Indian untouchables, who often adopt Buddhism to escape the humiliation of the Hindu caste system.

In the modern globalized age, private individual conversions are quite common, with the convert continuing to live peacefully as a full citizen, respecting his political and social culture. An American for example who adopts Buddhism is no less American for it. The Italian footballer, Roberto Baggio (famous for his pony tail and missing his penalty in the 1994 World Cup Final against Brasil) converted to Buddhism, but never rejected his Italian culture. However, when conversion, is not only both religious and political, but also requires the convert to reject the past, the results can be devastating.

In these surreal times of America's war on terror, certain western converts to Islam have made the news for all the wrong reasons and, in the minds of some westerners, confirmed their worst fears about Islam. John Walker Lindh, a comfortable, even privileged, young, white Californian, after converting to Islam, went to fight for the Taleban in Afghanistan. Richard Reid the "shoe-bomber", a mixed-race British citizen, became a Muslim while in prison and, after becoming radicalized, tried to blow up a plane with explosives hidden in his shoe. Jose Padilla, an American convert is still being detained for allegedly planning a dirt bomb attack. Most recently, Diren Barot, a British Hindu convert to Islam, was sentenced for 40 years for planning a series of pathologically violent attacks in Britain and New York. What made these young men turn so vehemently against their own countries after converting to Islam? What made them forget the past and abandon concern their own people?

A voluntary convert to any faith is by definition changing his identity but Islam is perhaps unique in the scope and profoundness of the changes it demands of those enter it. Islam, like Christianity, sees itself as a divinely sent historic force moving the human story towards a definite end. And like most of Christianity, Islam believes it possesses the absolute truth. It is not enough to believe in one universal God to be a Muslim. The convert must also accept that Mohammad is the final messenger, chosen by God to bring the perfected message of Islam, supplanting Christianity and Judaism, which by definition must be historically doomed. It is not clear why Allah kept Islam back for so long while he allowed the lesser truths of his other faiths to thrive for so long

Along with accepting the strident moral superiority of Islam, the convert's historic consciousness is re-directed. His history is now linked irrevocably to Islam's and he becomes part of a 1,400 year process. The causes of Islamic people become the convert's causes. The convert's sacred language is now Arabic, although he may not know word of it. Arabia also becomes sacred since Mecca and Medina are there. In short the convert acquires a radically new geo-political identity. How can such changes not alter the convert's psychology and sense of loyalty and belonging?

Along with altered political loyalties, some new converts to Islam also start dressing according to Islamic tradition. Take for example Islamist movements in Indonesia and Philippines, in which young Asian Muslims imitate Arabic appearance yet they have no ethnic, cultural or historic connection with anything Arabic, other than Islam. Older Muslims, both Arab and non-Arab, often dye their beards a reddish-orange color, for no other reason than that Mohammad did.

Islam is an openly political faith and for Islamists – those who believe Islam should be an imperial dominant force – there is no power above the Koran and a Muslim's only loyalty is to the Koran and the Islamic community or "ummah". In some minds, therefore, loyalty to Islam trumps nation, culture, class, race, language and even family. Such loyalty, while causing enough problems in largely homogenous Islamic countries, can create massive social upheaval and danger in secular societies, such as Britain and France, trying to assimilate their Muslim minorities. The danger is even greater with radicalized young converts, who are indoctrinated to regard their government and the majority non-Muslim population, not only as infidels, but as oppressors of Islam. Such zealous converts, eager to show their loyalty to Islam, and with the proper manipulation by older hands, can become walking time-bombs.

The convert may also be led into violence by Islamic teachings that split the world into camps, the House of Islam and peace and the House of War comprised of infidels or kafirs. Mainstream Islamic teaching openly declares that it is the duty of the Muslim to make war on the infidels until they are subdued, killed or converted. For Muslim male martyrs killed in such a struggle, Islam promises an instant, eternal paradise where beautiful virgins wait. It is difficult to say how many suicide bombers, if any, are actually driven to kill based on such an incredible promise.

Another reason why converts to Islam so completely reject their past is that Islam regards all pre-Islamic history as an era of darkness and polytheism.

This belief is difficult to understand given that Islam accepts that Allah himself sent the prophets of Judaism and Christianity into the world before Islam. However, despite this contradiction, Islamists, in many different countries and ages, have shown great hostility to pre-Islamic cultures. For example, the Taleban in 2001 destroyed the gigantic statutes of Buddha at Bamiyan in Afghanistan, precisely because this art pre-dated Islam and therefore, was deemed anti-Islamic. The clerics in Iran have great difficulty in accepting Iranians honoring any pre-Islamic practice such as "No Ruz" or new year. The past seems simply too dangerous for the identity that Islam demands.

Although Islamic teaching lies at the root of why converts turn against their own cultures and people, we cannot discount the individual convert's psychological state. A convert maybe who is alienated is more susceptible to an ideology that offers a community where he is welcomed and given a powerful new identity. Islam with its certainty replaces the convert's alienation with new meaning and purpose. In addition, young men who feel limited by racism and a feeling of powerlessness in a rapidly changing globalized world, where the wealthy seem to have it all, are suddenly infused with Islam's power. It is perhaps seductive to feel part of a glamorous international Islamic culture, and membership in a movement that promises to bring history under its control. Those searching for certainty and belief in an often surreal, post-modern world may believe that in Islam they have found not only salvation but also something worth dying for.