This chapter will:

discuss the difficulties involved in defining religion;

evaluate different disciplinary approaches to the study of religion;

examine the ways in which the category ‘religion’, and in particular the idea of so-called world religions, has been contested as a western Christian-influenced and modern concept that has come to shape how religions are viewed globally;

discuss the terms ‘secularization’, ‘secular’ and ‘secularism’, with a particular focus on the postcolonial deconstruction of these terms;

summarize the main challenges raised by this chapter for understanding the relationships between religions and mainstream development studies, policy and practice.