When I was studying for my history degree came across a few end of the world cults in the last 500 years or so. Think in the Reformation the Protestants thought biblical Babylon the Great was Roman Catholicism. There was another one too in the middle ages, they went to the top of a mountain to await the end, that's all I remember.
Why? Life is hard! It would be lovely if a powerful person came and fed the hungry, removed poverty, war ect. Sadly the longer we keep waiting for this mythical person the longer the suffering continues. We have to do it ourselves. We need to stop waiting for the Golden Age. (Google that phrase, very interesting).