The current sectarian conflicts in the Middle East did not arise solely from renewed geopolitical rivalries between regional powers. They are also rooted in a solid, theological articulation proposed by classic Islamic political theology. The exclusivist approach, which is a decisive part of the political, social and religious reality of today’s Middle-East, benefits from a formidable theological legacy. Coining the notion of ‘othering theology’, this paper not only explores the ideas of leading classical theologians who have articulated a puritanical understanding of faith, but also explicates the politico-historical context in which these theologians rationalised their quarrels. Given the pervasive presence of these theologies in the contemporary sectarian polemics, the study of classical othering theology is highly relevant and, indeed, crucial to any attempt to overcome sectarianism in the region.