This mortal life is a high-stakes gamble because we live in an entropic world - a world dominated by the tendency for destructive change, disease, decay, corruption and eventual death.
This is the world that our loving-parent God has created for us; and we must therefore assume that it is the best kind of world for His creative purposes and for our own individual ultimate benefit.
In the first place we need to understand that this mortal world is for our learning - our life is a kind of spiritual school. But why should this school be entropic?
The potential hazards of life in this mortal world are obvious - pain and misery in the short term, and damnation in the long term.
This means that the potential benefits of our lives must be even larger, great enough to outweigh the hazards (because the creator loves us, individually).
What is the advantage of entropy?
Entropy is the innate tendency towards destruction - and, in a broad sense; one advantage of this mortal life is that of discarding what is evil in us.
This is a conceptualization of repentance. By repenting sin, we 'leave it behind' when we are resurrected to eternal life.
Thus, our eternal selves will be free from sin, and fitted to live in Heaven while being free agents. Because our free choices will then always be Good: always aligned with God's will.
And this, in turn, means that we can be trusted with divine powers of creation, can our-selves become Sons of God and co-creators with God - adding to already-existing creation from our own unique (and sin-purged) selves.
Anyone can enter Heaven who - by repentance - consents to having his sins purged, stripped-away; but the more sins, the more will be stripped away.
Therefore, one of the hazards of mortal life is that we will become so sinful that, when it comes to resurrection, there will not be much left of us that is Good, and fit for Heaven.
This does not bar anyone from Heaven - because the power of repentance is unbounded, and anyone who follows Jesus Christ can be resurrected; but the Man who has led a deeply evil life before final repentance will be a lesser Man after resurrection than would otherwise have been the case.
This leads to one of the aims of the Devil.
His primary aim is that Men should choose damnation and reject Heaven; but even among the saved, the Devil (and his demonic and evil-human henchmen) gets secondary satisfaction from corrupting Men: that is, from encouraging sins that will reduce and impair the resurrected Man; and thereby diminish what might-have-been as resurrected Men enter Heaven.
(This corruption of individual Men does not make Heaven less-good - because Heaven is wholly Good, nothing evil is there. But it does diminish the stature of those resurrected Men who enter Heaven.)
So, this is a way of conceptualizing theosis - the process of becoming more divine in human life - because (to put it crudely) the more divine and less sinful we are in mortal life, the more of us there will be to resurrect and live eternally.
So, the plus-side of this entropic mortal world is that we can leave-behind sin; and this is necessary to salvation. The negative-side is that we may fall so far into sin that we either reject salvation (are damned); or by the end of our lives have very little left that is Good, so that even if we accept salvation - we will need to repent so many and bad sins, that we start-out as lesser Men when we resurrect.
So what of Heaven, which is a world of creation and without entropy?
In Heaven all is retained, life is cumulative.
Whereas in earthly life we change (partly) by leaving-behind; in Heaven we change by adding-to.
In mortal and entropic life; Men may transform radically, by deletions; in Heaven resurrected Men transform only by additions.
This scheme may help explain why this mortal life is entropic in its nature; and how such a hazardous life is nonetheless necessary and potentially useful, as a transitional experience between pre- and post-mortal existence, before a soul proceeds to the creative world of Heaven.
It also helps us to understand our own role in this life; and how our choices during mortality make a permanent difference to our potential after resurrection.