I think the whole book has been very interesting in light of recent political upheaval.
The whole time I was thinking that this book was very much about the ways in which people and societies cope with dramatic societal and political change. and further that that change was presented in a very distilled way by the way in which the cult finds new members. It inflicts massive violent physical trauma on the bodies of the person, just like civil wars and uprisings inflict damage upon a nation, then those that live through the violence are left to cope with the new worldview they are left with and with the damage to themselves.
Joining the cult offers these people an immiediate way to bring some new structure and understanding to their lives following this trauma, which can be seen in the searching of those in a post uprising situation scrabbling for a group or political movement to latch on to. and a sense of disgust at the life they had before.