I do not believe that there is anything supernatural. One of the consequences is that I avoid using the word spiritual. The word may have some merit as an historical poetic word.
I think that's very fair. It's surprising (bloody annoying?) how much the word is used without definition. The book I'm reading at the moment - Beyond the Burning Times: a Pagan and Christian in Dialogue - gives a couple of fair definitions. The Christian, Philip Johnson, points out its historic journey, from specific Roman Catholic theological term three centuries ago, through application to and use by other Christian denominations, where it referred broad brush to the interior shaping of individuals and communities in response to the particular emphases and understandings of their theology, and finally into general usage. The Pagan, Gus diZerega, summarizes the latest definition well: 'Spirituality is how we relate to the ultimate context of our being' (p.23).
According to diZerega's definition, Christians, Pagans and non-supernaturalists would each have a valid claim to the word, though as the Colonel points out, for the non-supernaturalist this might well involve viewing 'spirit' as a piece of poetry, a metaphor or useful myth, for the particular picture of the cosmos, and our place in it, that we develop over a lifetime. There's a recent book, for instance, by the French philosopher Andre Comte-Sponville, called The Book of Atheist Spirituality. It's on my to-read pile. Developing a spirituality, in this sense, would be a natural exercise in niche construction , as it pertains to ultimate meaning (or its absence).
There is, however, a problem with using the term strictly poetically if some of those listening believe 'spirit' to be actual, if intangible, stuff. That's why, I think, the Colonel wants to stress its historical nature, and, I'm guessing, would urge us to find new metaphors for issues pertaining to our interior life without recourse to terms drawn from out-dated worldviews.
None of which, as yet, commits me to a particular definition. So here goes:
Previously I have expressed my decision to leave behind all talk of the supernatural. This is because, although in my personal experience weird events have happened, it does not seem impossible to me for them to be simply some combination of random chance in a relativistic universe. Random chance, of course, includes random activity which biases subsequent events towards an increasingly complex state - as, for instance, in the case of evolution, or, perhaps, the micro-seconds post- Big Bang. If, however, within the nature of the universe, one could posit the existence of an absolute value around which that universe could transform itself, turning natural laws on their heads, or simply unfettering their grip for however brief or localized a time/place, would this be best thought of as supernatural or natural? Such a case, I think, can be made for the concept of love.
My personal take on the Christian story is that whether it happened or not, the core truth that it points to is that the ultimate transformative value is love, not religion. This rings true to me experientially, regardless of whether spirit exists or not. Indeed, if one then begins to build an imaginative picture of what love in its purest form is like, one becomes increasingly hard-pressed to find a need for a substance called spirit as well. Perhaps that is what the Bible means when it says that God is love.
For me, spirituality is all about the imaginative acts we engage in by which we come to realise the nature of love as a way of talking about the universe, and the nature of the universe as a way of talking about love. That sounds pretty Pagan. A more scientific answer would be to say that after several hundred thousand years (if not many million more) of conceptual development, it doesn't surprise me that some of our ideas have huge impact, or are immensely complicated, whilst others press us to get back to basics and simplify, deconstruct, rework. Such complexity allows for diversity as well as unity, poly- as well as monotheism. And it chimes with emergent scientific theory, too.
Ultimately, however, I (like you) live by experience, not my interpretation of it. So if, when I pop my clogs, I find that what I think I am has ensheathed something called spirit all along, I'll just, I reckon, have to take it in my stride! I'm juggling the Christian, the Pagan and the scientific worldviews. To conclude, therefore, when I use the word 'spirituality', I mean it technically, generally and poetically all at once, because my ultimate commitment, as a natural being, is to love, and to love is to be at ease with the juggling.
This is not a particularly clear or well-structured post, but I want my lunch!