In many metaphysically-based communities, it is a shared tenet that one cannot judge the personal experience of another. As a result of this tenet, these communities are dominated by something referred to as "Unverified Personal Gnosis". For those unfamiliar with the term, it is a phrase coined to describe those memories, insights, visions, and other metaphysical experiences unique to an individual. Combined with the tenet mentioned above, this has led to a sort of metaphysical version of the adage "God said it. I believe it. That settles it." As one can imagine, this has somewhat of a chilling effect on discussion, debate, and attempts to apply critical thinking and something aproximating the scientific method to the metaphysics of such communities, since it is invariably answered with the retort that one cannot argue with someone else's UPG because you have no way of knowing what they did or did not experience.
The problem with this line of thought, though, is that it doesn't actually lead anywhere. Sharing stories of UPG may be nice, but if all they ever are is UPG then what's the point? How is that ultimately any more valuable than sitting around and telling entirely made up stories that can also inspire and may contain tidbits of wisdom and truth? If I can get essentially the same effect from a good RPG or being part of a writers workshop as I can from being a member of a metaphysical community, I think something is wrong.
The biggest problem I have with the concept of Unverified Personal Gnosis is the unstated but undeniable premise that Unverified is equal in this context to Unverifiable. Whether it is memories or spirit-travel, visions or channeling, the standard response is that we must respect all experience equally. No effort is made to actually try to verify it. No research, no critical thought; indeed any attempts to apply these to the UPGs of others is met as an attempt to tear others memories/experience down in some way.
Personally, I'm far more interested in working with VPG. Verified (or at least Verifiable) Personal Gnosis. To be sure, it's not as easy as just stating a UPG and saying you believe it, so that settles it. For VPGs, you need to do a bit more homework.
The easiest form of VPG to work with is the shared memory. Where you and someone else independently remember scenes of substantial similarity, to the point where you can each provide details to flesh out the scene without prompting, and where each side holds certain randomly chosen details back until the other person mentions them to help verify it really is the same memory and not just something similar. This works best when the details that are held back are ones that are not easily extrapolated from other information, so that you can be certain it has in fact been independently remembered. Most of the past-life memory I work with and take seriously I have gone through this verification process with. And obviously, the more people who can independently verify details of shared memory, the stronger the verification is.
Obviously, though, not all personal gnosis is going to be shared, and even if it is it may be some time before you find someone who does share it. That doesn't mean that your personal gnosis is automatically impossible to verify. Another way to verify personal gnosis is to look for consistency. And there are two main types of consistency to look for. The first type, internal consistency, whether the elements of the gnosis agree with one another. Another word for this is continuity. A memory which involves the living incarnation of the concept of Peace going Rambo is probably not consistent. A large and thriving and ancient village of elves, old and wise and in tune with nature, needing someone to employ magic to ensure enough food to eat for dinner is also probably not too consistent, since even humans with their comparatively short life spans figured out ways to survive in harmony with nature and grow/gather/store enough food to not need magical assistance in this task.
The second type of consistency is external consistency. Whether the elements of your gnosis are consistent with observed reality. So, you think you were a hawk in a past life, or as your therioside. What kind of hawk? Are you even familiar with different species of hawk and their habits? How much do you know about your particular variety? If you look it up, is the information consistent with your memories/impressions? Or lets say you remember another world. This world has animals, people, plants, gaseous atmosphere, gravity, sun, moon or moons, running water, mountains, valleys; in short, many elements that resemble earth at various stages of its development, past present or future. Question is, how deep does it go?
Does it actually match what we know of how such things work, or does it have all the realism of a cardboard cutout? If there is wind, is there evidence of wind-based erosion? If there is water, is there evidence of water-based erosion? Are the geological features consistent with known geological processes? Are rivers associated with river valleys? If the oceans are salty, are wells dug near the ocean subject to salt water intrusion when they are overdrawn? Is there evidence of a full ecosystem, or only the more glamourous and/or magical animals? Are there more elven farmers than elven mages or warriors? Are warriors trained by experienced warriors or by high-born priests/priestesses? Is there evidence of politics, economy, philosophy, language, art, recreation, and culture? How well does your memory, or your personal gnosis, match those things that one would rationally expect in such a setting, and match our knowledge of how similar systems work on this world? If you remember a world with flowing water, mountains, valleys, oceans, and gravity, then rivers are going to flow to the sea. Two rivers/streams flowing very close to each other will always tend to flow into one another unless physically seperated by some means that they cannot erode.
These are just some means of working towards verifiability in your personal gnosis. I'm sure there are others. Let's start applying some critical thinking to our gnosis, actually doing our homework on the subjects. If your personal gnosis involves a dog deity, information on canine breeds and behavior and evolution may be at least as useful, if not more so, than information on the traditional myths and stories associated with this deity. Knowing about forest ecosystems may be of use in understanding a forest deity, and elements of climatology in dealing with storm gods. Let's ground our gnosis in the real world, and in consistency, rather than treating it like so much fanfiction and being afraid of anyone giving it a bad review. Is treating spirituality as something more than a fandom too much to ask?