An existence is "ineternal" if it is not eternal; if it has an end or a beginning. Part of the understanding of eternity, which we might call alternatively "of reality," is the recognition of the lack of worth possessed by--hypothetically, for an ineternal state can "possess" nothing--an ineternal state. It is this contradiction which Judaism resolved when it grew, through imitation, several arms of Europeoid-style philosophy and transformed itself into the many heresied and orthodox forms of Christianity, whereby the inherent wrongness of any kind of temporally finite existence made more advanced minds continue to reject associated philosophies, no matter how forcefully imposed.
An ineternal state should be easily recognizable to the modern (c. 2018) as a philosophical concept in the ways in which Bang religions privately instill the ineternal while publicly claiming believers shall have a part of a vicarious eternity. This private installation is easily likened to Bang religions of death, wherein components of memory are mandatorily deleted, if not by life, then by death. More simply put, consider the Bang notion of death, whereby memories vanish through forgetfulness during life, and are then cleaned up in totality by host death, where they are proven ineternal, wholly lost except inasmuch as they form a necessary component of another surviving entity's memory, much like a hot potato that is constantly being carried and causes a loss once its all is noticed. The hot potato must be dropped, of course; even the wisest scholars cannot help but eventually forget the one who was known by the one who was known by the one who was known, and the temporal context of meaning inherent in experiencing material records ensures that, over a very short period of time (say, fifty thousand years, which can seem very long to us until we use, say, a common star as a timekeeper), what was really meant was forgotten. Eventually, even the fact that someone once tried to mean something is also placed into the realm of the unprovably speculative.
The vicarious survivability offered by Bang is expressed as realistic in that it solidifies the notion that memories are unreliable, not only during the instant comprehension of life, but more so after the passage of time, rather totally immediately after death, and utterly once all those who knew the memory-gathering entity are also not present to recall their own memories of "what he knew." What this means is that, when you think you have experienced something, you have some part of it--tiny or massive, depending on the case--wrong, and however right you were, details begin to fade over the years, after which they may be lost forever due to the material degradation of long term storage facilities or, eventually, death. This returns to the original conflict between material existence as conduit, versus material existence as a series of definitive illusions. We may recognize the incompleteness, Terra-specific, or inherent stupidity of earlier versions of resolving this problem, whereby a giant invisible sky-server compiles, then returns, memories to their original spawners, as when our ideally-aged bodies are returned to Valhalla, or some version of a Christian Heaven, thereby providing a form of immortality, i.e., eternity. The specific details of why those fables give away their wishful nature, or why they are stupid, are an interesting subject, but not here the focus; whatever their failings, they are, nonetheless, wonderful, in the sense that they represent a reaching for eternity in the face of accusations of material-only illusionist philosophies, wherein existence is a passing lie that no one will remember.
We turn, here, to the reasons why an ineternal existence would be "unsatisfying," or more importantly, worthless, or still more importantly, impossible. If you are reading this, existence is not ineternal--but that is a more technical claim, much as the unsatisfying nature of ineternity would be more emotional. The focus here is on the worthlessness of any hypothetical ineternal existence, the recognition of which can do things to the mind that others cannot.
Firstly, though, what is the vicarious eternity which the Bang religion promises? Well, unlike Christianity, Bang does not save memories. Memories are suggested as a fatuous reinterpretation played at by later angels/super-scientists, where what they always were or have become is attributed to their forebears, which is supposed to make us happy. Posit that, after X thousand years of suffering mortality, we develop a technological immortality, and spread it across the stars, and after another X thousand years, immortal human-like creatures have so many backups that they are never defeated. People live pleasurable lives forever.
Now, this is not for us. Or if it is for some elderly member of us who is suddenly saved by an unexpectedly swift march of technology, it is not for a really nice person who died yesterday, or a hundred or a thousand years ago. In any case, our part in the "progress" toward the promised future is supposed to assuage us, despite the deletion of our and others' memories. This is what is meant by vicarious participation--we are part of forever not as what we see as our selves, but due to our material participation in a long-forgotten project of achieving, through material, the presumed desires of those who are yet to exist. The Bang religions are constantly trying to dial back notions of interaction with, or participation in, reality, a.k.a. eternity, and as many creative Christians over the years have attempted to massage notions of hell, paradise, and afterlife into more plausible stories, we have in some places seen any form of memory- or individuality-retention eliminated in favor of mass subsumption by an immortal, simultaneously unitary and multiplex god-paradise, wherein we are forever happy but not really ourselves anymore. Consider, e.g., the multifaceted, developing--and occasionally quite popular--notions that Hell isn't about endless drowning in lakes of lava, nor Heaven about endless perfect meals and sex, but that Hell is a less tangible, or intangible, "separation from God," and Heaven a "unification with Him." Quite related to developing Bang, these modern-artish, obfuscative, vaguely-defensible perspectives. The flat in the clouds, regular masses, and laureled feasts are replaced by "modern" indecipherable fantasies that can't plausibly contain the outdated specifics they once did.
The Worthlessness of Ineternity
In an important way, the proponents of cloudy penthouse condos where you meet Grandma again, even if they don't believe it in their private, scared moments, are often more intellectually advanced than those who recognize the flaws in such material shows. Grasping for eternity, even dishonestly, holds a superior truth in that regard, to its near sibling, namely the recognition that the great holy man is just making money. A finite existence is "so worthless" that it might as well not be had at all. Even as chattel for a future race of dimension-jumping pleasure-angels, it is not only unjust, but truly worthless.
We'll necessarily refer often to large time scales in such a discussion. For any quantity of finite time, we may just use "googol," even if the real number would turn out to be "ten million years" or "three hundred billion years" or "a googol googol googol years."
Memory deletion makes memories worthless. Take ten thousand years of human memory. Start with the major life experiences of, oh, one percent of the people who lived during that ten thousand years. Being vaguely content and happy that Mommy is there; being excited that now you can walk and decide what places you can get to; seeing something you want, and getting it; seeing yourself more grown, and imagining a fully-capable you; seeing someone of the opposite sex that you want, and getting it; having offspring; seeing offspring succeed at something; seeing offspring teach its offspring how to succeed at something; realizing it's going to end; that last moment. Throw into active memory the corresponding one percent of events "of historical significance" based on any selection bias you want. Spear developed; missile successfully launched; enemies successfully defeated. Throw in, too, one percent of significant individual achievements with same self-selected or random choice of bias: richest, lordliest, most powerful, truly good, truly pure, developed immortal technology--all of it.
Pass that ten thousand years. Then another. Then technological immortality is developed. At some point after that, universal data backups, instantly and constantly scanning, are developed. Everything prior to that is gone, except for the tracest pieces of scarce, incomplete, then-biased historical significance. People who spend their time learning about the past can only speculate about what untold quantities of information they've lost forever--if they even care. The greatest love, the finest melody, the most poignant sacrifice--gone.
Being here, now, on Terra 2018, comes with a similar, but amazingly smaller, set of metaphysical quandaries. The peoples who are, from our current perspective, gone and forgotten will be duplicated by whoever comes after, if a red giant Sol or a folding dimensional verse or just some damn local war wipe out everyone before they can escape. Survive all that, and a hypothetical finity still wins.
Worthless memories make everything worthless. Now bring that googol years into play. Then end the hypothetical finite existence.
The entire time, wiped out. Everything, everywhere, every time, that was good, bad, boring, currently- or retroactively-significant or not, is equalized in nonexistence. (If you're interested, you might find your own parallel between that and the inborn passion some have for advocating for material equality.) The greatest betrayal by the most treacherous entity in a googol years has utterly vanished, as has the greatest achievement by the most heroic entity in a googol years. No one is left to contemplate it. No one ever can or ever will. A googol years later, all the pleasure and satisfaction that it was amazing, is gone. It's not a question of no one caring or being able to care any longer so much as it isn't a question. It never was and never will be.
Everything in a hypothetical ineternal existence suffers this fate. The best art, the worst art, the best love, the coolest right hook to the jaw ever--not even gone, but never was, since the strictures of time, the guideposts of how matter behaves, don't exist. In actuality--sic--such a scenario is impossible.
We can thus conclude that, even if here we can't understand how, the absence of eternity is, for lack of a better word, "fatal" to anything. That time your pants fell down when you were accepting the award; that time you machine-gunned those forty nuns: irrelevant. When all balance sheets are going to be cleared--when all balance sheets can be cleared, at any time, for any non-reason, for all or one potential "reason"--that existence is so broken, so impossible, that anything that would happen inside it would be worthless. Honor, treachery, et cetera.
Believing in things or not believing in things. Another irrelevancy if it doesn't matter anyway. This one has long sought salvation in the materially appropriate mantra that if it doesn't matter then it doesn't matter anyway. Balm for the times.
The fundamental way that what we recognize here as Jewish monotheism "won over" Europe, and then Terra, was in taking a murder-god who wins and promises temporal material pleasure and adapting it to promises that, whatever the innumerable and differing details, there was an eternity. And selling you back something you already owned before you got here was a great way to amass material. And it--the inherent indignity, the "inhumanity" of that act--is important, is meaningful, only because there is always more.
The specifics about ineternal worthlessness are many and varied. It is Bang-popular, now, for the seemingly rich to adopt a carefree attitude toward finity, wherein things find a value because they're going away. That's quite literally insane as far as perspectives go; it is similar in form to the inversion-reverential belief that finite resources produce the only true, reliable, or sizable resources. Think of the argument that "making love on the beach after we had those margaritas only matters since it isn't an everyday thing."
A passing, then deleted (to the point of not having happened, due to the aforementioned destruction of time), un-contemplation of such finite resources is held to be the only experience one had, has, or shall ever have with any resource. The consideration of this problem, like the consideration of any zero, can lead to a systemic sort of understanding, whereby one so beguiled can recognize that the deal is bad; that one is promised nothing in exchange for (mentally) sacrificing something, even be that something a 0.00000~1% likelihood of a quantity of something. Versal laws of reality/eternity of course make the relevant quality "1" and not subject to permanent trade, but the deal is ridiculous if not bad. Ergo the 0.00~1% chance that an invisible omnipotent man with a passionate and extended interest in local sexual activities exists, who will provide eternal existence in exchange for blind belief, is a better deal than the nothingness offered as an alternative. Bang's need to dogmatize "potentially cycling universes," wherein folding dimensions recreate reality after each purge, is necessary even in the face of the identification of earlier myths, because the new deal (sic) is so bad that lies are necessary to force something down.
For those unfamiliar with Bangism, in the sense of "theoretical physics," we're discussing here the ways in which dark matter was hypothesized to balance spooky conclusions, replacing a cold nothing-unforever with an overhot crunching forever, physical laws made incomprehensibly malleable by forces unknown to mankind which will, at least, regenerate material existence after its cataclysmic failure. Differently put, this means that the math of initial Bang sects provided for a cold everdeath, in which the energy stored in stars by Bang's initial explosion would eventually fade out, making any level of existence impossible. The philosophical implications of this conclusion of nothingness were too staggering for Bang to maintain its popularity, ergo "Cold Death" was replaced by "Big Crunch," whereby matter not perceivable by man was conjectured, which would pull everything together again and recreate Bang-like conditions, permitting Lord Bang to perpetually regenerate the universe. The swallowing of the doomed cold of initial Bangism by "regenerating, perpetual universe" mirrors the way in which grim early Judaism adapted to persistent eternal desires to become forms of perpetual Christianity.
From a different perspective, the transitions are cyclical.