ABSTRACT Philosophy of religion has recently made a turn to lived religion, an approach which seeks to understand lived religion as it is experienced concretely by individual practitioners. However, this turn to lived religion has seen limited engagement with the notion of belonging. Belonging here refers to the felt sense of being part of a group – of insidership – along with the development of positive social ties and mutual affective concern. It is my contention in this paper that reflection (...) on this experience of belonging can improve our understanding of lived religion. In particular, I argue that human beings have an affective need to belong – a fundamental and affective need for belonging and positive social relationship which is felt in the body and rooted in human biology and evolutionary history. This paper makes the case for the affective need to belong, before examining its implications for understanding religion. It finds that the affectivity of belonging is capable of raising the affective salience of certain in-group beliefs, as well as creating affective hurdles to dissent, and in so doing can help to explain processes of religion conversion, sustained religious adherence, and religious disaffiliation. (shrink)