I want to defend a strange proposition: that what we call “religious” is better thought of as encompassed by the secular, rather than as distinct from it. We usually think of religion and secular life as two spheres of human activity, like circles in a Venn diagram which may overlap or have connections between them, but which are fundamentally distinct. The religious world deals with spirituality, existential questions, and god; the secular world deals with the mundane matters of work, the economy, and nonreligious culture. This distinction comes originally from Christian thought, and has remained influential even in today’s more secular times - so much so that many people don’t know that the distinction was originally itself the product of religious thought.
But this popular distinction flatters religion and demeans the secular. Think about it: we don’t normally assign an area of human activity or culture to its own special “realm”, distinct from all the others. Sport, for instance, does not exist in its own “sphere”, even though it has its own concerns and practices. Sport is meaningfully distinguishable from human activities which are not sport, but it exists under the heading of human culture more generally: it does not get hived off into a totally distinct realm. We understand that sport is one of the many things that human beings engage in, something that can give us a sense of purpose, meaning, and belonging, but that it is one subset of human culture - nothing more, nothing less.
Thinking of religion like this - as a component of the broader “secular” world, rather than its own distinct region of activity opposed to the secular - clarifies so many things. First, it helps us understand that religion is a subset of human meaning-making and community-building more generally: it is not particularly special in that regard, and can be viewed alongside other meaning-making and community-building activities. Second, it contextualizes religious claims to “specialness”, revealing them as a sort of unwarranted special pleading which leads us to treat religion more deferentially than other human pursuits. Finally, it enables us to view religion more clearly through the lenses of our scientific disciplines, clarifying why we can think of religion anthropologically, psychologically, sociologically etc. - because it is just human behavior, nothing more.
There’s another reason too why I, a Humanist, want to reconceptualize the “religious” as part of the broader secular world. Because I reject the existence of gods or other supernatural entities or powers, to me religion is just another human activity. It has no innate “specialness”, and should be treated similarly to other aspects of human culture. This means, further, that we can begin to ask what human needs religious practice meets - and retrofit or redesign those practices - outside of the metaphysical frameworks of traditional religions. By incorporating religious practice back into the broader family of human culture, we can better understand how people who are not traditionally religious can use religious practices to improve our lives. The metaphysical claims of religion are forced to relinquish their hold on what are seen, once again, as fundamentally human practices.