Leon Festinger attempted to explain why a UFO doomsday cult increased proselytization after the leaders prophecy failed. In his book, When Prophecy Fails, he tells how when the aliens did not destroy the earth as the cult leader predicted, that the cult changed its message to lesson the dissonance. They accepted the new prophecy that the aliens had spared the planet for their sake. Notice they changed their beliefs to reduce their dissonance.