We could have our own explanations and understanding of what the two words mean for us, however a kind of closer to the actual reality approach would be to examine the two terms on a deeper level.
| Meaning | Spiritual | Religious | |
| semantical | - | - | |
| ethimological | - | - | |
| lexical | - | - |
That's the kind of approach we should be looking for if we really want to reach the roots of the two words and see what they have in common and how they differ.
Such type of analyses exist in the thick books and some of them are definitely worth examining.
etymological? epistemological?
I'm not 100% sure if the epistemological is worth checking.
And true, some people dedicate their lives to semantic research... and that's cool. In general, I'm more interested in the less formal personal explanations... and how people arrive at them. I've read a few of the "thick books" along the way... and there's good information there, although (at least for my tastes) the issue I have there is that such texts often ignore the foibles and pettiness of human nature.