Unity is the Big Solution; Unity is the precursor of Peace; Unity is the Truth of All Religions . . .
Praise thou God that at last, through the divine teachings, thou hast obtained both sight and insight to the highest degree, and hast become firmly rooted in certitude and faith. It is my hope that others as well will achieve illumined eyes and hearing ears, and attain to everlasting life: that these many rivers, each flowing along in diverse and separated beds, will find their way back to the circumambient sea, and merge together and rise up in a single wave of surging oneness; that the unity of truth, through the power of God, will make these illusory differences to vanish away. This is the one essential: for if unity be gained, all other problems will disappear of themselves.
('Abdu'l-Bahá, Selections from the Writings of 'Abdu'l-Bahá, p. 29)
Tear asunder with the hand of Thy transcendent power, O my Lord, the veil of vain imaginings, that they who are wholly devoted to Thee may see Thee seated on the throne of Thy majesty, and the eyes of such as adore Thy unity may rejoice at the splendors of the glory of Thy face. The doors of hope have been shut against the hearts that long for Thee, O my Lord! Their keys are in Thy hands; open them by the power of Thy might and Thy sovereignty. Potent art Thou to do as Thou pleasest. Thou art, verily, the Almighty, the Beneficent.
(Bahá’u’lláh, Prayers and Meditations by Bahá’u’lláh, p. 7)
The foundation of the Divine teaching is this unity and harmony. Moses strove for unity among men; the Christ did all to promote this understanding, and Muhammad proclaimed the necessity of this union. The Buddha also worked for the same great goal. The Gospel, the Qur'án, and all Holy Writings are the basis for this unity.
(Lady Blomfield, The Chosen Highway, p. 173)
Do not give up those practices and do not break those rules which good Muslims have evolved or introduced before you, which have created unity and amity among the various sections of the society and which have benefited the masses.
(Ali b. Abi Taalib, Letters from Nahjul Balaagh)
(Mathnavi of Rumi (E.H. Whinfield tr), The Masnavi Vol 4)
...then came confusion between joy and anger, fraud between the simple and the cunning, recrimination between the virtuous and the evil-minded, slander between the honest and the liars, and the world order collapsed. Then the great virtue lost its unity, men's lives were frustrated. When there was a general rush for knowledge, the people's desires ever went beyond their possessions. The next thing was then to invent axes and saws, to kill by laws and statutes, to disfigure by chisels and awls. The empire seethed with discontent, the blame for which rests upon those who would interfere with the natural goodness of the heart of man.
(Tao, Chuangtse (Lin Yutang tr))