This is fascinating. Thank you for writing this! I'm intrigued with how legit psychology is mixed with other things to create a cult, and the tactics used to bind people to it. We all know something's wrong with us, and we'd give a lot to fix it!
Christians - Protestants, anyway - don't have secret knowledge that I'm aware of. That runs counter to our belief that the Bible is the core of Christian knowledge, and that no aspect of Christianity should be hidden from the laity. For instance, even in churches where women can't be ordained, women aren't prevented from knowing everything about the ordination process. I can't speak for Orthodoxy or Catholicism, though.