What is the significance of their discussion of religion? What does John argue religion can give to civilization? Why does Mond argue that it is unnecessary and potentially dangerous?

John and Mond's discussion parallels one that is within our society to a certain degree, the topic of religion and its significance to civilization. For starters, it's amazing that Mond even discusses such material with John. Savages in Brave New World are known for being uneducated and "less superior". Yet, to Mond (who is divergent to society in his own way) sees John as the exception, and is fascinated by his outlook on society. It's like he's never been able to have such a level of conversation like he has with John. Their conversation on Religion in particular is fascinating, because both John and Mond bring convincing arguments to the table to back up their claims. John believes that religion brings a moral code that is needed in society. That, if an available option to the people, would bring true freedom, because the people would have the right to choose. Mond, on the other hand, views religion as "unnecessary" and "potentially dangerous" to society. 

 "Call it the fault of civilization. God isn't compatible with machinery and scientific medicine and universal happiness. You must make your choice. Our civilization has chosen machinery and medicine and happiness. That's why I have to keep these books locked up in the safe. They're smut. People would be shocked it …" 

 Mond believes that God has removed himself from society to make room for universal happiness. For God and scientific advances were not compatible. The problem with the arguement he makes above is that the people have chosen happiness over religion. Yes, maybe at one time man chose this, but these descisions effected every generation onward. They werw stripped of their right to choose and didn't even care because they're programmed not to. In the end we come back to this theme of science & technology vs. Religion. Both try and set the guidelines of society. Science is factual and isn't a choice, but just because religion is faith based doesn't mean it should be taken out as a choice. That's one of the more prevalant totalitarian descisions made by the World Controllers in the novel.