"He (Bahá’u’lláh) pronounced prejudice—whether religious, racial, patriotic, political—the destroyer of the body politic."

"Sixty years ago Bahá’u’lláh was in Persia. Seventy years ago the Báb appeared there. These two Blessed Souls devoted Their lives to the foundation of international peace and love among mankind. They strove with heart and soul to establish the teachings by which divergent people might be brought together and no strife, rancor or hatred prevail. Bahá’u’lláh, addressing all humanity, said that Adam, the parent of mankind, may be likened to the tree of nativity upon which you are the leaves and blossoms. Inasmuch as your origin was one, you must now be united and agreed; you must consort with each other in joy and fragrance. He pronounced prejudice—whether religious, racial, patriotic, political—the destroyer of the body politic. He said that man must recognize the oneness of humanity, for all in origin belong to the same household, and all are servants of the same God. Therefore, mankind must continue in the state of fellowship and love, emulating the institutions of God and turning away from satanic promptings, for the divine bestowals bring forth unity and agreement, whereas satanic leadings induce hatred and war."

`Abdu'l-Bahá, The Promulgation of Universal Peace, p. 124 

13 May 1912
(excerpt from)Talk at Reception by New York Peace Society 
Hotel Astor, New York