All men will adhere to one religion, will have one common faith.

One of the great events which is to occur in the Day of the manifestation of that Incomparable Branch is the hoisting of the Standard of God among all nations. By this is meant that all nations and kindreds will be gathered together under the shadow of this Divine Banner, which is no other than the Lordly Branch itself, and will become a single nation. Religious and sectarian antagonism, the hostility of races and peoples, and differences among nations will be eliminated. All men will adhere to one religion, will have one common faith, will be blended into one race and become a single people. All will dwell in one common fatherland, which is the planet itself. Universal peace and concord will be established among all nations.

('Abdu'l-Bahá. Some Answered Questions. On the Influence of the Prophets. 12. Commentary of the Eleventh Chapter of Isaiah. Paragraphs. 4-7. Pgs. 73-75)