The oneness of humanity and its happiness are dependent on ...

 "One of the potentialities hidden in the realm of humanity was the capability or capacity of womanhood. Through the effulgent rays of divine illumination the capacity of woman has become so awakened and manifest in this age that equality of man and woman is an established fact….
And let it be known once more that until woman and man recognize and realize equality, social and political progress here or anywhere will not be possible. For the world of humanity consists of two parts or members: one is woman; the other is man. Until these two members are equal in strength, the oneness of humanity cannot be established, and the happiness and felicity of mankind will not be a reality. God willing, this is to be so.

`Abdu'l-Bahá, A Compilation on Women