Realization of the principle of the oneness of humanity is at once the goal and operating principle of Bahá’u’lláh’s revelation. Bahá’u’lláh compared the world of humanity to the human body. Within this organism, millions of cells, diverse in form and function, play their part in maintaining a healthy system. Similarly, harmonious relationships among individuals, communities, and institutions serve to sustain society and allow for the advancement of civilization.