Your point about making unsupported claims is well taken and a valid one. I have, as you point out, not provided any proof of my impressions or beliefs. Over the years, I have come to accept as true or correct, certain impressions or flashes of thought that come to me in a manner that I experience as extra-personal, meaning, not dependent upon a logical deduction on my part, unlooked for, unanticipated.
Call it intuition, inspiration or revelation. It's a subjective experience, as I noted in the article and as such is susceptible of criticism and doubt both by myself, and by any other party, but I find myself persisting in accepting such experiences as valid contacts with something beyond myself.
As far as "proving" such an experience, I don't think that I could, in the same way that I cannot "prove" an emotion to you, as the feeling or internal state is not directly transferable to another individual and is only (imperfectly) available to anyone else insofar as I am able to describe it verbally. Although I suppose one can track how emotions affect us physiologically and thus "prove" them to be manifestations of a biochemical state of affairs. I am not a psychobiologist and don't have enough expertise to say much of value on that topic.
In any case, accepting the premise that I will prove nothing, I may at least be able to explain my thinking.
I accept the existence of a spiritual aspect of our being for several reasons. I was raised in a religious environment and continue to be fairly active in the church that I attend. So, it would be entirely accurate to dismiss my thinking simply by saying that I accept that premise from habit, or from being inculcated with it. It makes me comfortable. There are other reasons, however, that I persist in believing in a spirit.
I have met more than a half dozen people who have had near death experiences, whose perception of that event was that their spirit separated from their physically apprehensible self. As a result, they came away accepting the idea of a spiritual aspect of our being. In fact, arguing about it with them seems tantamount to discussing whether or not their right arm exists and is attached to their bodies. It's simply pointless. (See
http://www.near-death.com/ if you're curious about these experiences).
In addition to my discussions with these individuals, several personal experiences have solidified my own belief in a spirit. Those experiences, though, were spontaneous and not something that I can "prove" by repetition, but they are the core of why I believe in a spiritual aspect of our being. If you're interested in a more detailed discussion of spiritual experience, take a look at William James' classic book "The Varieties of Religious Experience." James generally takes the stance that there are enough people reporting experiences with enough parallels that there is possibly something to what the prophets/mystics/visionaries say. In any case, this is a topic that won't be settled with two paragraphs of text (or a small library's worth, for that matter).
With regard to the nature of the spiritual aspect of ourselves, my thinking about that is highly informed by my religious tradition. I trust the ideas expressed about the nature of spirit because I have found other ideas expressed within the accepted theology of that tradition to be true. Within that tradition, the concept of a spirit is that it is made up of "matter" that is not apprehensible to our physical eyes (light, as it were), that it has agency, i.e., that it can make morally significant choices, that it is capable of growing or increasing in "size" (size being relative amount of light, as I understand it).
If you talk to any physicist, they'll tell you that the bulk of mass/energy in the universe is not physically apprehensible. Just for example, the residual radiant energy from the big bang literally fills our entire universe with light. We are awash in wavelengths that are beyond our physical capacity to see (check out NASA's site
http://map.gsfc.nasa.gov/ for images of that light and John Mather's book, "The Very First Light" for some interesting background.) It is also commonly accepted (based on mathematics that are way over my head) that there are states of mass/energy that are beyond the ability of any of our current instruments to measure or even detect. Some interesting books for the lay reader on that topic are:
"Just Six Numbers : The Deep Forces that Shape the Universe," by Martin Rees; "The Elegant Universe," by Brian Greene (my personal favorite); "The Bigger Bang," by James Lidsey; "Atom : An Odyssey from the Big Bang to Life on Earth ... and Beyond," by Lawrence Maxwell Krauss; "The Universe in a Nutshell," by Stephen Hawking.
In any case, given that the way we perceive the universe with our physical selves, including our perception of mass/energy, space and time, is just plain wrong, I don't find it that large a leap to believe in something that I cannot at the moment see, particularly when coupled with what I discussed above.
As for my accepting the existence of God, that is even more subjective than my reasons for belief in a spiritual aspect to humanity. Suffice it to say that various experiences have left me thoroughly convinced that God exists, is aware of us and loves us.
If you want philosophical arguments, I suppose you could read up on St. Anselm's proof, the argument from design and the various discussions of free will and the problem of evil ("Evil and the God of Love," by John Hick is a pretty good read). In the end, though, although I find them interesting, the philosophical arguments are not satisfying to me. I rely more on what I feel. Not much good for convincing anyone else, but not illogical either, I think. I can't pass on to you, for example, my relationship with my best friend. You have to build that on your own; get oil in your own lamp, as it were.
So, what does this very long-winded meandering have to do with bodybuilding?
The ideas I've discussed above had been kicking around in my head for a good while when I had the experience on my bike ride, as previously described. In a word, engaging in physical training modified my understanding of what I accept as the spiritual side of my being, as I explained in that first post. It put me in a position to grasp, intuitively, something about myself that I otherwise believe I would not have been open to.
You are, of course, entirely free to dismiss everything I've said as unsupported hogwash. But I am curious to see whether my unsupported hogwash resonates with anyone else out there.