Although Charles Williams was superficially a highly sociable man, full of energy and apparent optimism; deep down he was far more pessimistic than his freinds C.S Lewis and JRR Tolkien.
This is revealed in the late, great flowering of theology in the last decade of his life, and most of all the essay "What the cross means to me" (published as The Cross in the selected essays entitled The Image of the City edited by Anne Ridler, 1958).
Here are some excerpts, in order but re-paragraphed and re-punctuated:
The original act of creation can be believed to be good and charitable; it is credible that the Almighty God should deign to create beings to share His Joy.
It is credible that He should deign to increase their Joy by creating them with the power of free will so that their joy should be voluntary.
It is certain that if they have the power of choosing Joy in Him they must have the power of choosing the opposite of Joy in Him.
But it is not credible that a finite choice ought to result in an infinite distress...
...that the Creator should deliberately maintain and sustain His created universe in a state of infinite distress as a result of the choice.
This is the law which His will imposed upon His creation. It need not have been.
Our distress then is no doubt our gratuitous choice, but it is also His.
He could have willed us not to be after the Fall.
He did not.
Now the distress of the creation is so vehement and prolonged, so tortuous and torturing, that even naturally it is revolting to our sense of justice, much more supernaturally.
We are instructed that He contemplates, from His infinite felicity, the agonies of His creation, and deliberately maintains them in it.
The whole creation groaneth and travaileth together.
Williams conclusion is that at least, alone of all gods, the Christian God subjected himself to the justice which He established. But the sense of outrage is there.
The sense that God 'ought to' have annihilated the souls of those who chose against Him; rather than maintaining them eternally in torment.
(If that is indeed what happens.)
For Williams, the bedrock of human existence was apparently as described above: finite choice leading to infinite distress; mitigated only by a God who suffered along with His creation.
CS Lewis may have had Williams arguments in mind when he wrote the 'Hell' chapter of The Problem of Pain (1940) - excerpts:
In an earlier chapter it was admitted that the pain which alone could rouse the bad man to a knowledge that all was not well, might also lead to a ﬁnal and unrepented rebellion. And it has been admitted throughout that man has free will and that all gifts to him are therefore two-edged. From these premises it follows directly that the Divine labour to redeem the world cannot be certain of succeeding as regards every individual soul. Some will not be redeemed.
There is no doctrine which I would more willingly remove from Christianity than this, if it lay in my power. But it has the full support of Scripture and, specially, of Our Lord’s own words; it has always been held by Christendom; and it has the support of reason.
If a game is played, it must be possible to lose it. If the happiness of a creature lies in self-surrender, no one can make that surrender but himself (though many can help him to make it) and he may refuse.
I would pay any price to be able to say truthfully ‘All will be saved.’ But my reason retorts ‘Without their will, or with it?’ If I say ‘Without their will’ I at once perceive a contradiction; how can the supreme voluntary act of self-surrender be involuntary? If I say ‘With their will,’ my reason replies ‘How if they will not give in?’
The Dominical utterances about Hell, like all Dominical sayings, are addressed to the conscience and the will, not to our intellectual curiosity. When they have roused us into action by convincing us of a terrible possibility, they have done, probably, all they were intended to do; and if all the world were convinced Christians it would be unnecessary to say a word more on the subject.
As things are, however, this doctrine is one of the chief grounds on which Christianity is attacked as barbarous, and the goodness of God impugned. We are told that it is a detestable doctrine—and indeed, I too detest it from the bottom of my heart—and are reminded of the tragedies in human life which have come from believing it. Of the other tragedies which come from not believing it we are told less. For these reasons, and these alone, it becomes necessary to discuss the matter.
The problem is not simply that of a God who consigns some of His creatures to ﬁnal ruin. ... Christianity ... presents us with ... a God so full of mercy that He becomes man and dies by torture to avert that ﬁnal ruin from His creatures, and who yet, where that heroic remedy fails, seems unwilling, or even unable, to arrest the ruin by an act of mere power.
I said glibly a moment ago that I would pay ‘any price’ to remove this doctrine. I lied. I could not pay one-thousandth part of the price that God has already paid to remove thefact. And here is the real problem: so much mercy, yet still there is Hell.
I am not going to try to prove the doctrine tolerable. Let us make no mistake; it is not tolerable. But I think the doctrine can be shown to be moral, by a critique of the ob- jections ordinarily made, or felt, against it.
Finally, it is objected that the ultimate loss of a single soul means the defeat of omnipotence. And so it does. In creating beings with free will, omnipotence from the outset submits to the possibility of such defeat. What you call defeat, I call miracle: for to make things which are not Itself, and thus to become, in a sense, capable of being resisted by its own handiwork, is the most astonishing and unimaginable of all the feats we attribute to the Deity.
I willingly believe that the damned are, in one sense, successful, rebels to the end; that the doors of hell are locked on the inside. I do not mean that the ghosts may not wish to come out of hell, in the vague fashion wherein an envious man ‘wishes’ to be happy: but they certainly do not will even the ﬁrst preliminary stages of that self-abandon- ment through which alone the soul can reach any good. They enjoy forever the horrible freedom they have demanded, and are therefore self-enslaved: just as the blessed, forever submitting to obedience, become through all eternity more and more free.
In the long run the answer to all those who object to the doctrine of hell, is itself a question: ‘What are you asking God to do?’
To wipe out their past sins and, at all costs, to give them a fresh start, smoothing every difﬁculty and offering every miraculous help? But He has done so, on Calvary.
To forgive them? They will not be forgiven.
To leave them alone? Alas, I am afraid that is what He does.