Essay on Islamization is a study of the Islamization of all Muslim societies, their conversion to orthodox Islam which, with its chapels, soldier monks and holy war, leads to fundamentalism as well as to a moral puritanism. Cherkaoui gauges the importance of this global phenomenon by analyzing the empirical data of some sixty Muslim and non-Muslim societies. He also conducts two ethnographic surveys to identify the metamorphoses of Muslim religious practices and their causes.

Among the dozen theories put forward to explain these planetary phenomena, he cites those of secularization, modernization, the religious market, the influence of the media and the policy of donors of unlimited financial resources, social mobility, geopolitical causes, the emergence of fundamentalism and the role of "proletarian" intellectuals who promote Messianism, and social pressure.