Most in whom awakening is acknowledged will agree that there are universal, fundamental similarities. And there is much acknowledgment that some who attained awakening were corrupted by power.
Some newly awakened rant and rave that there is no such thing as enlightenment, because the awakening exposes the non separateness of the individual. And yet, one easily sees that enlightened words come from one "apparent' person, yet not from the rest of humanity. This makes it rather difficult for the common man to understand.
Perhaps a distinction needs to be made regarding gurus speaking of their impersonal condition, and the person seen speaking. For what is fact for the observer, there is a person there, despite whatever protests the guru may made. Even the guru must admit that there is a body the needs to eat, sleep, and have shelter.
If you define a guru as someone whose always blissed out, whose eyes glow with a faraway look, who doesn't have fear, and leaves ashes on objects he touches, we've certainly lost our way. If we had enough people fall into this condition we'd have a highly dysfunctional society, covered in ash, waiting to die out.
For the rest, for making it clear that although their basic experience is of non separation, impersonal experience, that there is in fact
May years ago I wrote a benchmark of guruship. It was picked up and placed on several major Hindu sites, so it must have had some universal application. You can verify this by clicking on these links. It is below.
Enlightenment experienced in a person cannot stay in the blissed out, ecstatic condition very easily and survive. In the West in particular you can end up in a mental institution, as did Robert Persig, the author of "Zen and the Art of Motorcycle Maintenance. He is fine now, enlightened, but certainly not dysfunctional.
Ramana Maharshi didn't speak for several years, and was near death when people started taking care of him. That does happen. But that is not the process for all gurus.
Is enlightenment just an idea, or does it have some basis in fact, in experience. Just like thirst, it can be spoken of, it can be experienced, but can you find it anywhere?