At the turn of the 21st century, the global resurgence of religion is posing a direct challenge to a Westphalian international system which upholds secular politics as the most peaceful, stable, and universal foundation for international relations. It is thus important to interrogate the secular dimension of the contemporary political foundation as well as the beliefs and assumptions that shape IR’s historical foresight so that international dialogue may be facilitated. Through the reconsideration of the secularisation process, I demonstrate that the Westphalian secular order emerged through the usurpation, translation, and appropriation of important religious resources found within Christianity. Far from being universal or neutral, the current foundation of international politics has theological origins and a religious character to which it is oblivious. In turn, this implies that secularism’s overconfidence in its own neutrality and objectivity may be a threat to the preservation of peace and security. In the name of value pluralism, IR must distance itself from its secularist history.