Christian-Muslim relations in Africa are still largely approached in terms of either religious conflict (a tendency that has gained more currency since the upsurge of Boko Haram in north-eastern Nigeria) or what scholars attempting to advance ecumenical ideas have called ‘interfaith dialogue’. These two approaches suffer from the same limitation: they take religious boundaries for granted. In an effort to open up the binary logic of an exclusive ‘either/or’ that permeates the study of religion and replace it by an inclusive ‘both/and’ paradigm (Lambek 2008), this paper presents an ethnographic case study of Chrislam: a series of religious movements that originated in Yorubaland in south-western Nigeria in the 1970s, which mix Christian and Muslim beliefs and practices. The core question leading my paper is: how to conceptualize processes of religious mixing without falling into the pitfall of assuming an essentialised purity, as was the case with much work on ‘syncretism’? The problem with syncretism is, as many scholars have remarked, that it presupposes the distinctness of religious traditions as the default and takes religious mixing as a deviation. Rather than religious boundedness as norm and religious fluidity as anomalous, in Yorubaland’s multi-religious field practices of religious plurality are a rule rather than an exception, as exemplified by Chrislam. I conclude that the answer to my question lies in ‘assemblage’, which I explore as an alternative heuristic device for mapping religious mixing. Inspired by Deleuze and Guattari (1987), I conclude that assemblage theory may help us to move beyond the problematic Africanization approach that syncretism draws on and to challenge the tendency to study religious traditions uniformly.