How we cite our quotes: Citations follow this format: (Chapter.Part.Paragraph)
Quote #19
"One of the numerous things in heaven and earth that these philosophers didn't dream about was this" (he waved his hand), "us, the modern world. 'You can only be independent of God while you've got youth and prosperity; independence won't take you safely to the end.' Well, we've now got youth and prosperity right up to the end. What follows? Evidently, that we can be independent of God. 'The religious sentiment will compensate us for all our losses.' But there aren't any losses for us to compensate; religious sentiment is superfluous. And why should we go hunting for a substitute for youthful desires, when youthful desires never fail? A substitute for distractions, when we go on enjoying all the old fooleries to the very last? What need have we of repose when our minds and bodies continue to delight in activity? of consolation, when we have soma? of something immovable, when there is the social order?" (17.20)
Mustapha's argument is incredibly relativistic—if God isn't needed by society, then God isn't there. He doesn't really address the terrifying possibility that God is there—and really, really angry.
Quote #20
"No, I think there quite probably is [a God] […] "But he manifests himself in different ways to different men. In premodern times he manifested himself as the being that's described in these books. Now…" […] "Well, he manifests himself as an absence; as though he weren't there at all." (17.22-6)
Ditto. (See thought above.)
Quote #21
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.