Government contracting with not-for-profit agencies, particularly those characterised as 'religious' and 'faith-based', to deliver social welfare has been the subject of substantial research in the United States and the United Kingdom in recent years. In contrast, attention to the role of 'religious' and 'faith-based' agencies in service delivery in Australia has been relatively limited. This paper explores conceptual issues relating to research into the impact on 'church-related' not-for-profit social welfare agencies in Australia of engagement in government contracting. It commences with a critical analysis of typologies in recent US and UK literature that use the terminology 'religious', 'faith-based' and 'secular', and identifies why this terminology is not analytically helpful. An alternative conceptual approach is developed, to guide research into the engagement of these agencies with government focusing on issues of governance, identity and mission. [ABSTRACT FROM AUTHOR]