The term naturalism arouses strong emotions; religious naturalism even more. In this essay, naturalism is explored in a variety of contexts, in contrast to supernaturalism (in metaphysics), normativism (in ethics and epistemology), and rationalism (in the philosophy of mind). It is argued that religious naturalism becomes a “thick” naturalism, a way of life rather than just a philosophical position. We can discern a subculture with a historical identity, a variety of dialects, stories that evoke attitudes and feelings, as well as more systematic theological elaborations. In this context, religious naturalists are called to thicken further the ways of life that embody their religious and naturalist sensitivities. In order to speak of a naturalist theology in this context, one has to define theology in a way that avoids assumptions regarding the supernatural; this can be achieved by presenting theologies as particular combinations of cosmologies (informed by the sciences) and axiologies (values).