The complexity of Naipaul's engagement with the issues which appear in his mature writings – the spiritual requirements of people, cultural heritage and historical determinism, and faith – is probably best gauged in his two books about Islamic countries and Islam: Among the Believers: An Islamic Journey (1981) and Beyond Belief: Islamic Excursions Among the Converted Peoples (1998). Both are travel books: clearly, despite asseverations to the contrary in A Turn in the South, that was not to be his last travel book. Among the Believers presents Naipaul's observations on Islam, Islamic states and Muslims in the course of travels in Iran, Pakistan, Malaysia and Indonesia in 1979; and Beyond Belief is a follow-up on Among the Believers, in which he describes his visits to the same countries sixteen years later. The two books together clarify some of Naipaul's thoughts on issues that held his interest. The clarification works at two levels. In the course of putting together details about his encounters with and thoughts about Islam he comes up with a perspective specifically on Islam, but he also manages to make points of general social, cultural and historical import. The two levels of clarification are concretized in the development between the two books (or between experiences which are separated by sixteen years). Among the Believers has an exploratory air about it: it comes to its subject matter with an assumption of ignorance, and the process of putting together and thinking about observations as they occur forms the substance of the book – though these are, tacitly, dependent on modes of cultural evaluation Naipaul had developed already. Beyond Belief has, naturally, an air of retrospection about it: it is more statemental in approach, and presents a concretized and confirmed thesis about Islam itself and about the general issues in question.

Among the Believers ostensibly sets out with a specific question: in what way do Muslims expect Islam to facilitate the creation of an ideal Islamic state, and what sort of concrete shape (in economic, technological and political terms) is the latter likely to take? This is the question which Naipaul repeatedly puts to those he meets in the four countries he visits, and he tries to meet those who are likely to be able to provide an answer.