What do we mean by religion?

Here there is a variety of views, four of which attempt to be definitions. Two of them are not: (d) is a psychological assessment and (e) is a comment on the function of religion in society, borrowed from Karl Marx. Of the four definitions offered, there could easily be concerns about adequacy. Religion certainly is about trying to lead a good life but is it not also about believing in certain things too? Religion is very difficult to fit into succinct definitions.