There are those people that believe somehow that what has physical form, such as a great pyramid, a planet, a sun, or even a solar system, are seemingly eternal in their existence, or something close to that. In actuality, nothing physical will last forever, nor is anything physical ever meant to last forever. Remember this well, that which has a known beginning, will, without exception, have a known end. There are no exceptions to that rule, so no matter how long of time we view such, we find that, in fact, eventually that which we even know as time, will itself, end.
The issue that most humans have is that they see their existence as being in a time-space continuum, and have difficulty conceiving of consciousness outside of that continuum, never considering the distinct possibility that this continuum is an artificial construct, never meant to be seen as lasting or as eternal, whatsoever. This thus signifies that our very existence cannot have started from our physical birth, or even before that, for we are ever the unborn, the eternal, and the changeless, and ever will be.
Yet, there are many that would scoff at the notice that we are changeless, for they see change in themselves, all of the time, and can easily prove such. Indeed, there appears to be some degree of paradox in the physical aspect of our being which does clearly change, as well as our consciousness which would appear to change by the very thoughts and deeds that we enact by virtue of our existence. However, as in something akin to a chameleon, or an actor up on a stage playing a role, our soul may indeed take on many guises, but as its core, our soul despite its countless forms, is in its essence, changeless.
So then, the reason why each of us needs to comprehend that the physical is finite in any of its many forms as it so appears to us in this human incarnation, is to provide to us, a serious reminder, that to overly concentrate our minds upon that which is physical, or of that which has been created, and not upon our eternal and everlasting Master Creator is to expend our energies upon that which is not truly worthy of such. Rather, we are meant to see this physical world, as the opportunity, to prove our mettle, by being good one to another, with the expressed understanding that we are all at our essence, one with God, and only our ignorance of such, and disobedience to such, precludes us from the correct comprehension that we are, in actuality, always the immaculate image of God.
This physical world and our incarnation upon it, seems to be, for many a person, the only reality, but in actuality, it is not anything more than an artificial construct, providing us with the fair opportunity to reflect the goodness of God, and therefore to bring light to those that are in ignorance or denial, so that their journey back to the eternal sanctuary of God can be safely actualized.