David and Mrs. Carmody become de facto leaders of two factions within the store: (1) the sane people, (guess which ones those are the believers or the non believers!) who try to work out plans to protect themselves, and (2) the doomsday apocalypse mongers, who see these events as payback for the sinful ways of mankind. Mrs. Carmody's agenda is a little shaky, but I think she wants lots of followers, and I wouldn't put the idea of human sacrifice beyond her (of course not, shes a god believer, whats one or two more sacrifices for god!). Religion always shows you just what its all about! If you are a non believer and use logic they're so willing to burn you or scarifice you the first chance they get. Watch!
Religious Freaks try to camouflauge their racism and xenophobia in many ways. They will be nice to you. They will shake your hand and wish you the best. Do not be fooled! It is always inside of them. It will come out. Just give it time and you will see it rear its ugly head.