I'm outlining a story where I want the main character to have an atheist belief system, but one which has some definite metaphysical beliefs, holidays, standards of behavior, etc. One of the specific ones I've thought of so far is that the main character should believe it is inappropriate for her to enter a building dedicated to a different religion. I also want her beliefs to be generally utilitarian and/or humanist. More on the socialist/communist side than the capitalist side. More on the hedonist side than the stoic, ascetic, or minimalist side. So can anyone suggest an actual religion or philosophy I can could have her be a member of, or is there nothing that would fit? Wikipedia only lists buddhism, hinduism, and jainism as non-theistic religions, and none of those are very close to what I'm looking for.