It is said that the Buddha’s true teachings would be lost in 500 or 1000 years. No one can say, but if they were, would it not be the interference of self-centered delusion? This is just one viewset, not particularly of one school or another (or myself, as I’m on the fence about much)… not as an argument piece, but maybe a different way we might examine our views without a hint of "personal" re-emergence after this life. The idea came about when contemplating that the metaphoric may have been misconstrued as literal at some point and the teachings distorted. Seriously don’t get all mad at me and call me a heretic or anything, this is just an exercise.
This is a future without the “I” in it, declining an eternity view or a doctrine of self, or any view that gives rise to “personal” involvement beyond this temporary life. It’s the most difficult view for a human to handle, fully accepting their impermanency and that life goes on without them, recycling their borrowed atoms; yet in positive fashion preserving, either known or unknown to humankind, the good they have done. Each word spoken, each act done in skillful fashion generates wholesome conditions; if toward other life, those conditions are “passed on”. This could be viewed as the Bodhisattva ideal, if not for other differing views associated with that concept.
Samsara = suffering born of Ignorance that leads to unsatisfactoriness/frustration (Dukkha), recurring throughout a human’s life until all Ignorance has been abated through acquisition of Insight into the reality of mind and all phenomena.
Karma (personal) = thoughts, speech and actions which create conditions (seeds) that have the potential to ripen as wholesome or unwholesome mental states. Also as “cause and effect”, karma can bear immediate fruit. The focus of this teaching is on mental processes alone; concerned with suffering and the cessation of suffering that results from Ignorance. Hearing the Dharma can give rise to conditions leading to this path.
Karma (impersonal) = the sum total of conditions that give rise to each moment, marking the interdependence of all temporary things. Based upon this impersonal karma are temporary formations arisen (even children require the karma of both parents and more); the more impact, the longer the effect on clinging-based (history/tradition) humans (i.e., the continuing effects of the speech/actions of The Buddha and Jesus).
Nirvana = the cessation of Samsaric suffering through elimination of Ignorance. Never separate, never born (unborn). No further identity/self view, knowing all things are impermanent and conditioned, acting out of compassion for the suffering of others with full right view of reality with no thought of personal gain.
Rebirth (metaphorical & personal) = the re-arising of unwholesome states of mind that lead to suffering, each conditioned moment of “Samsara”. With an understanding of Karma (cause and effect) as it applies to the chain of Dependent Origination to cause suffering, proper effort is taken to bring about conditions leading to Nirvana. Rebirth & Karma are two necessary parts of the same teaching.
Rebirth (literal & selfless) = the transformation of all temporary phenomena into new temporary phenomena, as governed by Impermanence, Karma and Conditionality.
EDIT: It is useful to reflect that in the earlier teachings, the focus is on liberation. In the next evolution, the focus is pulled back and the perspective shifts to be rebirth-oriented (though of course moving to emphasize compassion in lieu of wisdom). In the next-next evolution, even a framework for the rebirth in-between state (bardo) comes to be and personal reincarnation takes root. I absolutely could not say for sure, but doesn't it seem like it's exactly moving toward "self"-preservation, perhaps in very subtle fashion that speaks to our underlying self-centered desires? And what about Pure Land? It's very confusing, and we forever argue because of these differing perspectives. (This is not to advocate or denigrate any particular schools. IMHO they all contain teachings that can lead to the truth and are worthy of respect for the things they each do well also. It's just something to ask yourself, and hopefully have your own honest opinion about even taking into account the school you've chosen for yourself as your self-assessed preference, no affront intended whatsoever trust me.