The earth is but one country

The day is approaching when all the peoples of the world will have adopted one universal language and one common script. When this is achieved, to whatsoever city a man may journey, it shall be as if he were entering his own home. These things are obligatory and absolutely essential. It is incumbent upon every man of insight and understanding to strive to translate that which hath been written into reality and action….
That one indeed is a man who, today, dedicateth himself to the service of the entire human race. The Great Being saith: Blessed and happy is he that ariseth to promote the best interests of the peoples and kindreds of the earth. In another passage He hath proclaimed: It is not for him to pride himself who loveth his own country, but rather for him who loveth the whole world. The earth is but one country, and mankind its citizens.

Gleanings From the Writings of Bahá’u’lláh