The successive Founders of all past Religions Who, from time immemorial, have shed, with ever-increasing intensity, the splendor of one common Revelation at the various stages which have marked the advance of mankind towards maturity may thus, in a sense, be regarded as preliminary Manifestations, anticipating and paving the way for the advent of that Day of Days when the whole earth will have fructified and the tree of humanity will have yielded its destined fruit.
- Shoghi Effendi (‘The Unfoldment of World Civilization’)