There are fifty-six God-realized souls in the world at all times. They are always one in consciousness. They are always different in function. For the most part, they live and work apart from and unknown to the general public; but five, who act in a sense as a directing body, always work in public and attain public prominence and importance. These are known as Sadgurus, or Perfect Masters.
In Avataric periods the Avatar, as the Supreme Sadguru, takes His place as the head of this body and of the spiritual hierarchy as a whole. [Every advent of the Avatar (the God-Man, the Messiah, the Buddha, the Christ, the Rasool) is the direct descent of God on earth in human form-as the Eternal Living Perfect Master. The five Sadgurus of the age precipitate this advent once in a cyclic period of 700 to 1400 years. For details see God Speaks by Meher Baba.-ED]
– Discourses, 7th Ed, p268