After Tolkien; George Bernard Shaw was the first grown-up author I read - and I read a great deal of his work, much of it several times. But my favourite was the play Man and Superman (1901-3) - which combined a scintillating comedy with an underlying seriousness about 'life'.
In the 'preface' to M&S, Shaw described his deepest belief in what he termed Creative Evolution; which was a blind, impersonal Life Force struggling (by trial and error) towards greater self-awareness of Life, higher consciousness... the Superman of the title (from Nietzche's Ubermensch) is the future Man who has evolved-developed to a higher state of consciousness. This theme structures but is hardly visible in the play as it is performed; but may be found in a long interpolated, Platonic dialogue-type, dream sequence sometimes called Don Juan in Hell.
For many years, I would probably have described myself as a believer in Creative Evolution - so it is interesting to look back now and see what it was that appealed to me about the idea; and in what ways it failed. And Creative Evolution eventually did fail for me, comprehensively and wholly; as did the Fabian (gradualist, rationalist, egalitarian) socialism that I also absorbed from Shaw.
It appealed because it started-from the assumption that there was no God, that the whole idea was ridiculous - and that was my own assumption. But then it tries to generate personal meaning and purpose in Life despite there being no God - and this is its failure.
Perceiving the need for a purpose in reality is a good thing, compared with the arbitrary world of deterministic science. But having that purpose as an impersonal one that merely 'uses' individual human lives then casts them aside on the 'scrapheap', means that there is no reason for the Life purpose to be one that would engage my personal efforts. If ultimate reality is abstract, then there is no place for humans, and no place for me personally.
Why should I care about what the Life Force is aiming-at - any more than I care about what gravity or magnetism are aiming-at? I don't dedicate my best creative efforts towards hastening the work of gravity - why then an equally 'physical' and mechanistic Life Force?
Therefore to try and use Creative Evolution as a justification or reason for anything I might do, or not do, is incoherent - hence in practice CE has near zero effect on a person's life.
Insofar as it does have an effect this is due to an implicit but denied theism, the idea that the Life Force is really a god, and that the god is one who care about us and to whom we may choose to show allegiance in pursuing that god's aim. But the CE idea is set up specifically to deny such theism, so one gets stuck in a useless half-way house between theism and atheism.
Shaw's rejection of Christianity was, as is usual, rooted in a lazy and ignorant rejection of the simplifications and distortions of his childhood religion; without making any attempt to modify those simplifications and distortions - but instead throwing it out wholesale.
So, the fact that the religion of Shaw's childhood had at its centre an anthropomorphised god of (mostly) cruelty and the demand for blind obedience led Shaw to reject Christianity - instead of discovering the real nature of God for himself; and discovering that there is no error in personalising God (after all God is, for Christians, a person) - but only in wrongly personalising God - imputing to God characteristics that are covertly designed to serve social expedience.
(Shaw actually favoured inventing a God/ religion to serve social, specifically socialist, expedience; but he denied the real-reality of such a God/ Religion: it was merely a fiction designed by wiser and more intelligent rulers to control the young, ignorant or imbecilic 'little people' for their own - material - benefit.)
This type of Christianity-rejection is very common, and reveals a pretty deep sin - because people don't behave that way about the many other false or oversimplified things they are taught in childhood. We don't reject science or history wholesale just because the primary teacher told us wrong things about them. We don't become anarchists just because the methods of discipline ('stand in the corner', 'sit on the naughty step') experienced as a child strike us as ridiculously childish. We don't stop eating food because we have have grown to dislike the mashed rusks we were fed as a baby.
Instead, we set out to develop an adult understanding of these things. How few do this with Christianity! (I didn't.) Instead, people take the crudest distortions of Christianity, the greatest abuses; and insist that these are the essence and reality of it.
It is as if people are looking-for-excuses to stop being Christian - and that is indeed the case. Usually, the reason is not far to seek, and it is sexual - as it seems to have been with Shaw himself.
His deletion of God and substitution of Creative Evolution rationalised his preaching against marriage and families - and advocating a kind of eugenic fantasy of unconstrained sex between the most intelligent men (such as himself, and the hero of Man and Superman) and the most beautiful women - on the basis that this may lead to the best hereditary outcomes, and a step toward The Superman. The state would look after the resulting children, to leave the parents unconstrained. The unfit would be allowed to breed, but their children would not be supported, and be allowed to die-out. And so on...
There is thus a horrible clash in M&S between the idealism of the preface and play, and the reductionist materialism of the 'Revolutionist's Handbook' published as an appendix, which is supposed to have been written by the hero of the play. It reveals the essential vacuity of Creative Evolution, because - lacking any idea of God - the socialistic 'rational plan' to encourage The Superman is merely a set of legal and political regulations that might serve to breed stronger and more attractive farm and factory animals; but which can have nothing to do with encouraging a higher form, or species, of Man.
On the other hand, and to give Shaw his due; he did not ever fully succumb to the mainstream materialism of his age; and his best plays (i.e. most of those written up-to and including Major Barbara - before he was fifty years old) have both vitality and also intimations of awareness that there are higher strivings and something better. And the most-idealistic/ least-materialist, the most spiritually striving, characters often are given 'the last word' in the Shavian debates.
The later Shaw (and he lived nearly another fifty productive years) suffered a relative decline of spontaneity and heart; and seemed (with a relatively brief exceptions, and never again at the pre-1905 level of quality) almost to cease genuine engagement with Life - often merely to be seeking public attention and spouting words in colossal quantities.
(Several of his later plays are indeed very good, by normal standards for plays, and have held their place in the repertoire - Doctor's Dilemma, Heartbreak House, Androcles, St Joan, Pygmalion, Apple Cart for instance; but they are none are as good as the best earlier ones - e.g. Arms and the Man, Candida, Devil's Disciple, Caesar and Cleopatra and - outstanding in its power - John Bull's Other Island.)
But like many of the greatest imaginative writers (such as JRR Tolkien and CS Lewis), Shaw's 'fiction' (i.e. his plays) are deeper and more complete than his prose essays. Indeed, his plays reveal the defects of his explicit beliefs. For example Shaw's plays reveal the deficiencies of Shaw's own person - since he often included characters who were - essentially - himself': such as Trefusis in Unsocial Socialist (a novel), Charteris in Philanderer, Caesar, Dick Dudgeon in Devil's Disciple - and John Tanner in Man and Superman. Tanner's limitations, his incoherence, his hypocrisy, his blindness to human nature and motivation... all this is starkly revealed; even as he is also presented as cool, fluent, witty; and dominant over all other stage characters (excepting one).
In sum: Read Man and Superman. It is one of the best plays in English, and - I should say - the best comedy outside of Shakespeare; and far more perfectly-made and continuously-enjoyable than anything by Shakespeare.
In writing the play Shaw was trying for a Mozartian atmosphere - explicitly that of Don Giovanni. Shaw succeeds in being Mozartian, albeit much more like the glittering, exhilarating, supreme-fluency with hints of poignancy of The Marriage of Figaro.