Religion

Is religion a useless concept? Would we be better off without it?
The point is: once we subtract actual faiths or religious practices (Christianity, animism, Judaism....) from it, what's left?
The problem with maintaining the notion 'religion' outside of such institutions of religious practice is that the term becomes available too widely, meaning leaks from it. Pantheism, socialism etc can become thought of as 'religions' in some sense that is stranded between the metaphoric and the literal, and which obsfucates rather than clarifies thought.