A lot of modern people find it difficult or even impossible to square the basic and overall nature of Christianity with some descriptions of God's final judgement; in which our perfectly-loving Heavenly Father seems to be taking delight in consigning great masses of people to everlasting and unimaginable torment for what seem like rather trivial errors, incompetence, gullibility, ignorance and minor misdemeanours.
They are not necessarily wrong: some descriptions of the Last Judgement are clearly based on such utterly different premises and ways of understanding that they really don't make sense at all in light of what sincere and real modern Christians can understand of the nature of their faith.
So, unless we can come up with a better while still valid description of Judgement, then this will be a very serious stumbling block for some of the people who would potentially make 'the best' Christians - those people naturally abundant in love, compassion, and fairness.
Judgement is when resurrected Man, after death, is confronted by reality, and is made to understand it.
Then Man must choose - and this choice is God's judgement.
Either choose to acknowledge the primary authority, truth, beauty and virtue of God, to submit to the judgement of reality; and to join with God in pursuing His divine plan.
Or Man will choose his own primary authority; each Man therefore locating truth, beauty and virtue in himself - and judging God and the divine plan by his own lights, and resolving to pursue his own individual plans.
Man has the power to reject God; God respects that power and gives Man what he has chosen. In one sense Man judges God and rejects Him; in another sense God judges Man by accepting that rejection.
There is nothing strange or difficult about this understanding. A loving mortal human parent, and earthly father for instance, does much the same with his children when they grow-up. The analogy is close (although not, of course, exact in all respects).
A grown-up child can choose to remain part of his loving earthly family, and joined to the adventures and aspirations of that family in the world - he can remain a part of that loving network; or else the grown-up child can reject his family, cut himself off from the family, live existentially separate from the family, cease to love that family.
A good earthly father must respect that grown-up child's decision, yet without ever ceasing to love the child who has rejected him and his love, and the love of all the family.
And that father may become angry if the rejecting-child tries to poison the minds of the family, torments or exploits the family; the earthly father may need to be stern, and may need to exclude the rejecting and malicious child (whom, nonetheless, he continues sorrowfully to love).
The rejecting child has, in effect, chosen to live in a hell of pride, ego and isolation: perhaps a state of eternal torment. The loving father accepts this choice with sorrow...
- however the father's angry and stern judgement may insist that the chosen hell in which the rejecting child dwells is segregated from the family, is elsewhere than the family home - that the rejecting child is excluded from the family - and that the loving and innocent are to a sufficient extent protected from the direct and insatiable depredations of those who have chosen to dwell in hell.
Why final judgment? Because it may be final - a choice may never be reversed.
But the two situations of salvation and damnation are not symmetrical. Salvation cannot in principle be reversed - because of its nature salvation is a one-way ratchet of spiritual progress; while damnation is a self-chosen doom of a type that our earthly experience shows may in practice be irreversible (the miserable, hate-and-resentment-filled addict to drugs, sex, or violence may in practice never repent).
The choice of salvation therefore caanot be reversed, while the choice of damnation may not be reversed.
Choice and judgement: Two sides of the same coin. Love and sorrow; anger and sternness - likewise.