After offering a brief overview of the role of faith within Judaism, Christianity and Islam, an interdisciplinary analysis of faith, belief, belief systems and the act of believing is undertaken. The debate over the nature of doctrine between George Lindbeck and Alister McGrath brings into focus four ways in which beliefs can be employed: expressive, interpretative, formative and referential/relational. An analysis of monotheistic belief ensues which demonstrates how it can function meaningfully in each of these modes, including the last, where insights from phenomenology and relational ontology, as well as philosophical theology, favour a participatory approach in which God is encountered not as an object of investigation, but as that transcendent Other whose worship is the fulfilment of human being. The study concludes by highlighting convergences between the nature of faith presented in the initial scriptural overview and that developed throughout the rest of the study.