This essay has four main parts. (1) Reviewing previous theories of religion, it suggests that it may be helpful not to conflate, a priori, the notions of (the) religious on the one hand and religion\s on the other, and that it may be useful to explore concepts such as (the) sacred and transcendence as independent yet related to the business of theorizing religion. (2) Distinguishing social/cultural from biological/genetic evolution, it outlines the occurrence of three processes/stages of the evolution of religious affairs and religions(s), here called attributive, structural, and functional differentiation respectively. While the first two processes/stages occurred in the remote and ancient past respectively, the third process/stage is typical of modernities and has by now globalized. (3) The article argues that recent criticisms of the validity of the category of religion are informed by a reverse sui generis approach characterized by a tacit claim that religion is an anomaly, by virtue of its supposedly being inherently different from similar concepts. The article suggests that John Searle’s philosophy may throw light on the mode of existence (ontology) of religion as an example of social and institutional reality, as an intentionality- and observer-relative yet real and empowering structure. (4) In the final section, the article engages some lines of thinking of Bruno Latour’s interpretation of Actor-Network-Theory, in particular the category of non-humans and the importance of things (objects) for social reality, including religion.