In the "Bayan" the Bab says that every religion of
the past was fit to become universal. The only reason why they failed to attain
that mark was the incompetence of their followers. He then proceeds to give a
definite promise that this would not be the fate of the revelation of "Him
Whom God would make manifest", that it will become universal and include
all the people of the world.
- Shoghi Effendi (From a letter dated 20 February 1932 written on
behalf of Shoghi Effendi to an individual believer; The Compilation of
Compilations, vol. II, Living the Life)