Bahá’í Sacred Writings, ‘Abdu’l-Bahá, #296
Moreover, in this wondrous Dispensation the earth will become another earth and the world of humanity will be arrayed with perfect composure and adornment. Strife, contention, and bloodshed will give way to peace, sincerity, and harmony. Among the nations, peoples, kindreds, and governments, love and amity will prevail and cooperation and close connection will be firmly established. Ultimately, war will be entirely banned, and when the laws of the Most Holy Book are enacted, arguments and disputes will, with perfect justice, be settled before a universal tribunal of governments and peoples, and any difficulties which may arise will be resolved. The five continents of the world will become as one, its divers nations will become one nation, the earth will become one homeland, and the human race will become one people. Countries will be so intimately connected, and peoples and nations so commingled and united, that the human race will become as one family and one kindred. The light of heavenly love will shine and the gloomy darkness of hatred and enmity will be dispelled as far as possible. Universal peace will raise its pavilion in the midmost heart of creation and the blessed Tree of Life will so grow and flourish as to stretch its sheltering shade over the East and the West. Strong and weak, rich and poor, contending kindreds and hostile nations—which are like the wolf and the lamb, the leopard and kid, the lion and the calf—will treat one another with the utmost love, unity, justice, and equity. The earth will be filled with knowledge and learning, with the realities and mysteries of creation, and with the knowledge of God….
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.