I see it differently. IMO the "crazy religious stuff" is a tool adopted by LVD to gain power to manipulate others using their gullibility and fear about the state of the world around them. Just as the sexual appeal and sing-song cadence of her voice are tools to manipulate men and the tornado of talking and accusatory tones are tools to manipulate those who prefer to avoid conflict. She is a master at identifying and exploiting other people's vulnerabilities and weaknesses.
I think it likely that she saw the power Chad seemed to have over others with his stories about the coming end times and the chosen people and she wanted to share in that. And I do believe she had a particular inclination to have that in her life because when young she saw her own father as a "spiritual giant" and saw what she believed were the magnificent possibilities in having that power. IMO, the pursuit of that power and the adoption of the stories that would provide it is not the same thing as "religious delusions."
MOO and I do respect those who see it differently. We simply cannot know what is truly in her mind because we are reliant on her to tell us and she is a world-class liar.
But I do think it is a big "tell" that she is very selective about when and with whom she shares details. She has kept the truth about exactly what happened with JJ and Tylee within the small conspirator group (LVD, Chad, Alex) while lying to close others who shared in the doomsday teachings by implying that the kids were secured somewhere safe. (And more recently the lie has become "family tragedies" that include wrongdoing on Tylee's part.). She shared details with those people about fringe teachings while keeping the lid on those teachings with others who weren't part of those groups. And there don't seem to be any apparent signs that she was actually "preparing" as others in the fringe groups were - no building up of stores of food, charcoal, supplies. And she and Chad went off to Hawaii - rather than staying in Rexburg where these groups apparently believed the second coming or the preparation for it was to be.
To me, LVD uses the doomsday stuff like Manson used "Helter-Skelter." Neither really believed it; they both just saw the value of the power of those ideas in manipulating others and escaping accountability themselves.