Mu is the name of a [link|http://www.win.ne.jp/~eileenl/poleshift/mu&at1.html|mythical continent] (sister to Atlantis) that vanished. Add in usual stuff about lost civilizations, etc. (Add in usual stuff about plate tectonics, etc for why this is bull.)

By definition any religions they had would (according to believers) predate any we know about today. Add in appropriate mumbo-jumbo (eg past life regression), and voila! Make up whatever you want and The Ancient Teachings of Mu have been rediscovered! (Plus they conveniently say what you want them to say. Funny how that works.)

Of course talking in this way demonstrates that I have an excess of left-brain thinking preventing me from finding the inner truth of the Universe. (Convenient line that, anything anyone says that smacks of logic is now ruled out of bounds. Get someone to believe that and you are golden!)

Cheers,
Ben