Quote 37
"They say that it is the fear of death and of what comes after death that makes men turn to religion as they advance in years. But my own experience has given me the conviction that, quite apart from any such terrors or imaginings, the religious sentiment tends to develop as we grow older; to develop because, as the passions grow calm, as the fancy and sensibilities are less excited and less excitable, our reason becomes less troubled in its working, less obscured by the images, desires and distractions, in which it used to be absorbed; whereupon God emerges as from behind a cloud; our soul feels, sees, turns towards the source of all light; turns naturally and inevitably; […] Yes, we inevitably turn to God; for this religious sentiment is of its nature so pure, so delightful to the soul that experiences it, that it makes up to us for all our other losses." (17.20)
This would seem to be the way that John experiences religion; there are certain, key moments in the text where he obtains sudden resolve, where he claims sudden clarity or instantaneous revelation.
Quote 38
The Savage interrupted him. "But isn't it natural to feel there's a God?"
"You might as well ask if it's natural to do up one's trousers with zippers," said the Controller sarcastically. […] One believes things because one has been conditioned to believe them. Finding bad reasons for what one believes for other bad reasons—that's philosophy. People believe in God because they've been conditioned to." (17.29-30)
This is a great point—and it's passages like these that make some scholars believe Brave New World is a critique of any sort of religion. As readers, we rebel against the notion of hypnopaedia because it seems to us like brainwashing; but from this point of view, religious doctrine isn't too different.
Quote 39
"Do you remember that bit in King Lear?" said the Savage at last. "'The gods are just and of our pleasant vices make instruments to plague us; the dark and vicious place where thee he got cost him his eyes,' and Edmund answers—you remember, he's wounded, he's dying—'Thou hast spoken right; 'tis true. The wheel has come full circle; I am here.' What about that now? Doesn't there seem to be a God managing things, punishing, rewarding?"
"Well, does there?" questioned the Controller in his turn. "You can indulge in any number of pleasant vices […] and run no risks of having your eyes put out." (17.34-5)
Mustapha refuses to take into account any conception of divine justice or the afterlife. If there are no punishments during life, in Mustapha's mind there must be no punishments at all.