This topic is vague and open-ended. I'm leaving it that way deliberately. Perhaps some interesting, better defined topics will grow out of it. Or perhaps it's too far afield from the concept of less wrong cognition to be of interest here. So I view this topic as exploratory rather than as an attempt to solve a specific problem.
What useful purposes does religion serve? Are any of these purposes non-supernaturalistic in nature? What is success for a religion and what elements of a religion tend to cause it to become successful? How would you design a "rational religion", if such an entity is possible? How and why would a religion with that design become successful and serve a useful purpose? What are the relationships between aspects of a religion, and outcomes involving that religion? For example, Catholicism discourages birth control. Lack of birth control encourages higher birthrates among Catholics. This encourages there to be a larger number of Catholics in the next generation than would otherwise be the case, Surely there are other relationships like this? How do aspects of religion cause them to evolve differently over time?
Unfortunately, I can't give a good definition for this except by example. Christianity, Judaism, Islam, Buddhism, Daoism, Hinduism, Atheism. I suppose that it might even be possible to ask the questions assuming that science is a religion. The focus of the questions is intended to be on the engineering and social aspects, rather than on a question like "Should Atheism be considered a religion?" I understand that the vagueness makes this a less than perfect delineation of a topic.
Atheism shouldn't be thought of as a (single) religion for the same reason non-apples aren't a (single) type of fruit.