As regards your teaching work: the Guardian has already advised you to
stress in your talks the idea of a world superstate, and the concept of the
Oneness of Mankind underlying it. In addition, he wishes you also to emphasize
the fact that humanity, taken as a whole, has entered the most critical and
momentous stage of its evolution, the stage of maturity. This idea of the
coming of age of mankind constitutes the central core of the Bahá’í
Teachings, and is the most distinguishing feature of the Revelation of
Bahá’u’lláh. A proper understanding of this concept gives the key to an
adequate appreciation of the tremendous claim made by the Author of the Faith,
both with regard to His own station, and to the incomparable greatness of His
Dispensation.
(12 October 1936 to an individual believer) [63]