I'm partial to this one:
"Suppose there’s a group traveling about your area, led by a charismatic speaker who claims the world is ending soon. He promises he alone can save you, but you must sell your belongings, devote your life to him, and cut off family members who try to stop you.
He may also assign you a new name / identity, advise you to leave your home and job in order to follow him, and says that if you don’t love him more than your own family then you’re not worthy of him. His followers wrote a book about him in which he performs many miraculous feats, but no contemporaneous outside source corroborates these claims. What sort of group is that?"