As soon as Man emerged from his original state of immersive participation; as soon as he became became capable of conscious independent thinking - which happened (so far as we know) in the time of the ancient Greeks; it was recognized that this earthly, mortal life cannot be everything.
Cannot be everything - not that it 'should not' be everything; nor that we wish that there would be more - but that It Makes No Sense to assume that there is nothing other than this earthly, mortal life.
Well, in a sense this was so obvious to anyone capable of thinking and understanding that 'why' did not apply.
But the reason was - in a nutshell - that this world is one of change; of degeneration, decay, disease and eventual death. This is a world dominated by entropy, as we might call it. And such a world as this could not bring itself about.
To the ancient mind, and to the mind of pretty much all Men up to the past few hundred years - this was an insight of simple truth; and the only reason for someone Not to reach this understanding, was either mental incapacity or idleness: a brutish refusal to consider the nature of Man's life.
But Modern Man has - for various reasons, not-unconnected-with brutish incapacity and idleness - developed a tremendous capacity for doubting the obvious, including obvious truth.
There are explanations that explain 'why' it makes no sense to posit entropy without previous creation, to assume a tendency for destruction and death without a prior and more powerful tendency for making and life - but no such explanation can penetrate the idle, delirious, dishonest superficiality that characterizes modern discourse.
Such is the ludicrous pride of almost all Men, now, that the grossest incapacity of insight, observation and reason are paraded as marks of superiority; just as the inability spontaneously to be appalled or disgusted by gross, calculated lying, pride, greed, even vice and sadism - are all regarded as evidence of a 'higher' more progressive morality!
'Ancient' Man realized that this ephemeral and always-changing reality makes no sense unless there is another reality.
All were agreed on that - but disagreed about the specific nature of that 'other and greater reality' - the reality which makes possible the illusions and changes of this reality.
They disagreed about the nature of the other and Real reality for the simple reason that it was non-obvious; and impossible to articulate clearly, concisely and comprehensibly to all Men. Each attempted answer, each description of ultimate reality, was therefore partial and contextual - and there were many such answers.
In other words, it was cognitively easy to know that this mortal earthly reality was only a part of a greater reality; but it was difficult to say exactly what was this greater and eternal reality.
Modern Man is, however, incapable (has rendered-himself incapable) of recognizing that the difficulty of describing the wholeness of reality in a way that everybody can understand and agree-upon does Not invalidate the primary insight that there Must be such a reality.
Instead, Modern Man has made the baseline assumption that this mortal earthly life dominated by entropy and inevitably terminated by death is every-thing there is; and that (somehow!) We Know this to be a solid fact!
Based on this assumption of this-life being everything, nothing makes sense; all is incoherence.
Because all is incoherence, Men have lost the capacity to reason.
Because Men cannot reason, they cannot make sense of the world - it is just one thing after another - and Men cannot even discern motivated actions, nor discern evil in motivations.
Because Modern Man can make no sense of life; life has neither meaning nor purpose, but only a cloudy and uncertain present that arises-from nothing-much, and soon disappears into nothing-much.
Thus Modern Man is always afraid, and cannot be encouraged; his only antidote to spontaneous overwhelming despair is to not-think even harder than already.
The condition of Man is now very, Very bad - far worse than is recognized even by vehement critics.
A refusal to know that which is both obvious and deeply true, makes an extreme incapacity to think consecutively on any one subject - meaning that recognition of even the most blatant lying (and all other evils) is become impossible.
Modern Man is therefore deep in trouble, and a measure of this depth is that his 'solution' is not to eliminate the problem; but instead to eliminate all trace of his own awareness of the problem.
His answer is to keep digging at his own deficits until he has become completely unable to recognize anything beyond whatever is being fed-into his consciousness at this moment.
Having written-himself-off as nothing more than an ephemeral accident of blind chance; Man has rendered himself incapable of motivated thought and action; and now (un-consciously, because he will not allow consciousness) seeks to become altogether passive and receptive; to eliminate awareness of even the fact of his own, self-defined-as-futile existence.
The modern malaise goes very deep; consequently its ramifications are extremely wide.
We can see that its roots lie in sin, in unacknowledged hence un-repented sin; and this is why it keeps getting worse and worse - because evil feeds-upon evil.
In theory, the remedy is at-hand: (thanks to Jesus Christ) simply one turn of the mind distant. Graspable in a moment.
But evil has its layers of defence; its clever-silly rationalizations that reject the obvious and therefore can impose belief in the false; its ingrained and socially-supported habits of distraction and fear-driven resentment.
Only each Man himself can escape these toils; but he must first desire to escape...
And therein lies the most intractable problem of all.