No god definable? There are lots of gods (little "g") that are defined, Paganism is full of them, that's a small part of the problem we are up against here. But now "G-d," big "G," is another matter. How does one define the undefinable? That's a human tendency to limit the limitless, and it says more about the lack of imagination on the part of the person who would disqualify the possibility of G-d in such an offhand way. Granted, the proof is in the pudding, and according to the definitions of proof and evidence there are no solid proofs or evidences for the existance of G-d...but there is plenty of circumstantial evidence of G-d. Many a case has been convicted in a court of law on nothing more than circumstantial evidence.
I suppose my candidates for circumstantial evidence would be those isolated figures in history for whom there is both unaffiliated and hagiographic "press" and for whom some direct experience of deity seems claimed by the actual individual. They should also be seen making such claims in the very earliest extant text on their story/sayings, and their "walk" should never be seen as substantively clashing with their "talk", even in the least affiliated and most unsympathetic texts. That actually narrows the field considerably. There are dozens of figures for whom claims of direct deitic experience have been claimed, but frequently, these claims involve figures of whom one can see an occasional "fall" in their "walk", despite a generally upright nature for
most of their actions. Often, it seems impossible to find relatively unaffiliated or neutral texts on some of these people (Moses, for example, even though he does seem to have become one of the most upright of them all, after his killing in hot blood a very cruel slave driver when he was a very young man). Confucius, a very upright man who did start a new creed, is always at pains to stress in the earliest stratum of the Analects that his is the "second" kind of knowledge from reading, not the "first" kind of knowledge of the instinctive sage. Not all these figures are entirely free from ultimately warlike actions that can strike us as clashing with their frequent pronouncements against killing the unarmed. And so it goes.
Once we winnow such figures, there seem only three who consistently walk their talk, are cited in occasionally unaffiliated texts, and have direct claims of direct deitic experience in the earliest extant texts: Buddha, Socrates and Christ. Sticking strictly with the earliest extant stratum of textual material on these three, all that one can really say of deity is that the notion of an afterlife remains murky (Socrates in the earliest texts is ambivalent about this), the degree to which deity was responsible for creation is also uncertain (Buddha fails to bear this out), and the degree to which deity controls everything that happens is also inconsistent, going from text to text on each of these three.
What does emerge consistently from these three and their earliest documentation, though, is that deity is something quite tangible and that it is a very direct inspiration for the most keen types of social conscience amongst humanity. That social conscience seems expressed most directly as a universally generous urge of giving and caring for all, and a sensibility that is the polar opposite from self-centeredness. Beyond that, the rest seems still uncertain. But if we take deity as being, at least, an energy of some kind that impels other-centeredness, then that, I'm guessing, would not be contradicted in any of the most intimately experiential sources for deity that written history has afforded us (i.e., these three figures).
Not much to go on, and still circumstantial only, yes. But a useful start all the same, IMO.
Best,
Operacast