Rebirth and Essentials
Persistence of experience, in a continuous event during the time we are alive gives the mistaken impression that, if we pay insufficient attention, we may reach the conclusion that we who experience do not change, and are something other than the changing physical animal we are. Insight into the error of supposing an essence which sustains experience and endures beyond it is the benefit of learning the truth of the principle of Anatman or Anatta.
The desire for such a continuity and endurance may lead us to affirm it and find reasons to promise and explain it, and this is what led to doctrines of essentialism and also to the teachings of rebirth in Buddhism. Taken as a metaphor, we are reborn each and every day upon waking in the sense that, using the raw materials of memory and the rudiments of our character, we reconstruct once more reflecting on the actions (karma) attributed to our cause the glamour of being a particular person with unchanging features, when in fact what is happening is the resumption of our attachment to this narrative and the particular character it preserves.
The same metaphor allows for an interpretation of the *quality* of past, present, or future experiences as 'heaven(ly)' or 'hell(ish)', yet need not have anything to do with experience which occurs after we die.
In consideration of dreams versus waking experience, the former are of a different character and conform to different principles. Dreams are less enduring and rational, are dependent solely on imagination for their content, whereas the waking world is far more consistent and has a physical basis of function and endurance. Knowledge of the latter is easy to acquire and just involves careful reflection and testing. Departure from this functional basis is one of the clearest indicators of being in a dreamstate.
The expansive significance of refusing to comment on what is not currently operative (gods or demons being present or absent, death presenting a continuity or discontinuity of experience, for examples) allows us also to refuse to comment upon what The Buddha did or did not say or do in any particular event.
Outside the confines of a sangha wherein doctrines are outlined as practical platforms from which one may benefit in supposing their veracity, believing or ceasing to believe things is inconsequential, save that it informs one's own motivation and response. This will have bearing on what steps will be taken to participate in or catalyze one's own realization, and so decisions of this type can become crucial in following the Path, abandoning it, or becoming lost in delusion.
Within the foregoing it might be transparent that certain conventions are supposed effective or authentic, such as the existence of the Path or Marga, the efficacy at least in part of the sangha or congregation of aspirants in walking this Path, and most importantly, the possibility of realization and insight which might arise from walking it.
The only warnings i have repeatedly received relating to beliefs or doctrines have in fact pertained to essentiality, and were characterized as Essentialism and Nihilism, these being coupled as twin errors of extremity. Whether one's ideas adhere to main schools, if one's beliefs could be identified as core to Buddhism so-called, or even if the Four Noble Truths or Eight-Fold Path were defined differently, this seemed far less problematic than to suppose there exists a central substance from which all of reality arises which itself does not change, or to suppose that the constantly changing quality of the cosmos indicates that nothing exists at all.