The religion believes in reincarnation, but that you will be reborn in the past. People of today are those re-born of tomorrow, with some discarded as trash. The most pure will be eventually reborn in the mythical paradise-like past, where people lived for hundreds, or maybe even thousands of years.

This goes nicely with beliefs into foresight (you know a little about the future because you have been there), but also to many complaints of how things are going always from bad to worse.