Central to the main theme of this book is the notion that there is nothing natural or self-evident about such religious categories as ‘Hindu’, ‘Muslim’, or, in particular, ‘Sikh’. Due to the nature of religion in Indian society, these categories are fluid and ambiguous in that they did not possess a pure form. “Historically, it is more precise to speak in terms of simultaneity of religious identities rather than distinct, universal, religious collectives" [1, p. 418]. By utilizing history and anthropology, Oberoi constructs an ‘ethnohistorical approach’; in which he explores the formation and distribution of ideologies which would coalesce into the Tat Khalsa episteme that would eventually be associated with the standard Sikh identity. The blurred boundaries became distinct in that the Tat Khalsa had ‘framed’ the modern Sikh community. By viewing this progression within the Sikh community, Oberoi hopes to reveal the “entire process underlying the rise and dissolution of a episteme" [1, p. 30].
He begins by recounting the first attempts by the Khalsa in the later eighteenth-century to establish boundaries by establishing concepts of self and other through life-cycle rituals, taboo behavior, transgressions, and the constitution of sacred space. Next he explores the displacement of the Khalsa episteme by the Sanatan Tradition and its transmission through the Dasam Granth; a sacred text that was used by and/or promoted the three major forces of change: guru lineage, holy men, and traditional intellectuals. The mixing of Khalsa and Sahajdhari texts, theology, and social practices formed a bricolage; which deeply transformed Sikh thinking and conduct. Whereas the Sanatan Tradition is viewed as belonging to the elite, rural Sikhs also participated in ‘popular religion’; which varied village to village and consisted of a plurality of religious beliefs and conducts. Despite the dissimilarities, these two forms of religious expression coexisted until the encroachment of Colonial Christianity forced a unification of the Sikh identity in lieu of a perceived decline of the Sikh population. In order to preserve the Sanatan Tradition from the repercussions of military defeat, the misidentification of Colonial census, and the inroads of Christian missionaries, the Singh Sabha formed to record and codify Sikh customs and practices. Most Sanatanists recognized a plurality of beliefs but in following the European logic the Singh Sabha strove to form a rational and uniform tradition. A new ‘elite sub-culture’ utilized the advantages of nineteenth-century modernization to influence the formation of the Tat Khalsa with which to purge the religious diversity within the Singh Sabha tradition. Puritanism, asceticism, and restraint were touted in the construction of a neo-Sikh moral community and the establishment of the Adi Granth as the sole religious text. In the ensuing struggle the elite Tat Khalsa and the non-elite Sanatan Sikhs demonstrated a clash of ideals reflecting divergent world-views. Faced with the prevailing attitudes that the Sikhs would not be able to compete with other religious communities for jobs and facing a possible loss of cultural independence, the neo-Sikhs established schools in which the Sikh community identified themselves with the Tat Khalsa and eventually this identity defined Sikhism.
Through this account, Oberoi demonstrates that the reification of the Sikh religion is not the simple product of British policy or the compulsions of elite politics, but rather the result of a complex evolution within religious, political, and economical domains.
 Oberoi, H. (1994). The Construction of Religious Boundaries: Culture, Identity, and Diversity in the Sikh Tradition. Chicago: The University of Chicago Press. ISBN: 0-226-61593-6