One universal Cause, one common Faith (Bahaism)

"That which the Lord hath ordained as the sovereign remedy and mightiest instrument for the healing of all the world is the union of all its peoples in one universal Cause, one common Faith. This can in no wise be achieved except through the power of a skilled, an all-powerful and inspired Physician. This, verily, is the truth, and all else naught but error."

(Baha'u'llah, Gleanings from the writings of Baha'u'llah, p. 255)