Mysteries 

For probably all of the worlds history the Mysteries have been imparted to suitably prepared people.  The Mysteries usually have been taught outside of the official churches, which led to Secret Societies since one with additional useful Knowledge did not wish to be punished by the official churches by being Burned at the Stake after being tortured.  Thou shalt not piss off a Religion if that religion has a lot of power.  It is better to spit into the wind or even to mess around with Jim.

The Mysteries have been called the noble orders of architecture or as soul building.

Some saints such has St. John and St. Paul were trained in the Mysteries. 

It has been said that Jesus Christ was learned in the Mysteries. 

Parts of Freemasonry are referred to as the Mysteries of Freemasonry.