Drawing upon a qualitative exploration of the role of faith-based organisations (FBOs) in service provision for homeless people in the UK, this paper examines the ways in which the ‘faith’ in ‘faith-based’ services is articulated and experienced ‘on the ground’. It demonstrates that the ‘F’ in FBO is expressed in a myriad of nuanced ways, and that the strength of ‘coupling’ between many welfare agencies and organised religion has diminished over time such that some projects’ faith affiliation or heritage is now evident in palimpsest only. Homeless people do in fact often find it difficult to discern tangible differences between avowedly ‘faith-based’ and ‘secular’ projects, given a blurring of boundaries between the religious and the secular. These findings problematise FBO typologies, and highlight the complexity and fluidity of the very concept of ‘FBO’ itself. Certainly, they suggest that the differences between faith-based and secular provision should not be exaggerated, whilst recognising the importance of faith to the motivations of many service providers and the potential value of the (optional) ‘spiritual’ support offered by most FBOs.