There's an assumption inherent to your phrasing of the issue, though: that an aura would have a "form" that should exist independent of the observer.
Not exactly. As an example, consider the color "red". While any number of people with "normal" vision upon seeing a red object agree to the "redness", there is no way of determining if "red" has the same physiological impact on all of them. No way to determine if the sensation of distinguishing red from green is the same for all. And, of course, there are those individuals who cannot distinguish the two, as well as those that cannot see either.
So, I am quite willing to believe that some people (most, I would say) are incapable of experiencing auras. And it is no great stretch of the imagination to contemplate people able to experience auras but not capable of distinguishing between aural qualities. It is still within the realm of reason that the description of auras given by those who can experience them to those that can't would differ, just as the attempts of those with sight to explain a scene to those without would differ. All of that I can accept and still consider the existence of auras a valid possibility.
But if auras have an objective existence and any significance, then the meaning of an aura should be the same to all who experience it independent of the sensation by which they experience it. Again, as an example, say that a person's state of health is shown in an aura. Say that to one person capable of experiencing an aura, bad health of a given type gives the sensation of "red". That to another it gives that of "choppy". Then, every time the first person experiences a "red" aura, the second person should experience a "choppy" aura. And conversely, the second person should experience "choppy" only when the first experiences "red".
Now, the above is not strictly true. It could be that one or the other of the people experiencing the aura is aurally "color blind" (or tone deaf). However, if there is repeated and consistent failure to agree amongst many people claiming to experience auras, then the question of whether there is anything there to agree about is a valid question.
I'll freely admit that my example could be wrong in many details. That, for instance, an aura gives no information of the physical, only of the spiritual. That the experience cannot be translated into that of any of the other senses (as, indeed the experience of one sense cannot be described by the others -- there is no taste corresponding to "green" although there might be an association in an individual's mind). But, the underlying principle is, I think, valid. If the aura has any meaning, that meaning should be independent of how it is "filtered". And the same filter, applied to the same signal, should give the same result. Different filters might give different results on the same signal, but the results of all the filters should be consistent for similar signals.
Now, if this is not the case, then either the auras are meaningless (i.e., carry no information -- are just noise devoid of signal) or do not exist. There is no way to distinguish the two cases, and the principle of simplicity says that given the two hypotheses: "There is no aura" and "There is an aura but it cannot be measured, it conveys no information, and it exists only because a few people claim it exists", the first hypothesis is the one to accept.
And note that there is nothing of science in the argument. Simply common sense. The common sense that lets us see the humor in "The other night upon the stairs I saw a man who wasn't there . . ."
Your notion that something must be proven to be of value is your prerogative, but any who adopt that standard will, by definition, cut themselves off from spirituality.
If, by spirituality you mean table tapping and ghostly noises, then yes, a skeptic will throw that nonsense out. If by spirituality you mean the belief in a higher being, then no, I do not reject that as a possibility that others may accept. I do reject anything tied to that that defies common sense while offering no proof. I reject claims that a small group of persons have superior powers that they cannot demonstrate and that do not give self or mutually consistent results.
There's a spiritual principle that applies: you shall know the tree by the fruit it bears.
And when neither the tree or the fruit can be produced, then what? "Thou shall know the fruit by the witness of those that have tasted it"? "Thou shall know the witness of those who have tasted it by the witness of those they told"? You imply that, because I will not accept the tree without evidence of the tree, the fruit, a seed, or even a paring of the peel that somehow I am narrow minded. Why then should I not accept the delusions of any person, sane or insane. Why not accept the claims of every charlatan that comes down the road?
That is the way of my pursuit, to be more persuaded by my experience than your logic.
I have described the method I use to distinguish what I choose to believe, what I choose to disbelieve and what I reserve judgment on. I have invited you to describe your method, and all you say is that you are "persuaded by your experience". But it is well known and easily demonstrable that the experience of our senses is unreliable. That things often (maybe even usually) aren't what they seem. So, again I ask, what filter do you use to determine true experiences from chimeras? How do you verify that what you thought you experienced was not a hallucination? Or even that your interpretation of what you experienced was actually the same as what you actually experienced?
You claim a different world view from mine. And you often imply that yours is somehow richer. You claim a superior means for determining "TRUTH", while I claim but a weak method to determine some "truths". If indeed you have access to such a world through such a method, then why do you not share it? And if you do not share it, why should I accept its existence?