The source of perfect unity and love in the world of existence is the bond and oneness of reality. When the divine and fundamental reality enters human hearts and lives, it conserves and protects all states and conditions of mankind, establishing that intrinsic(belonging naturally固有)oneness of the world of humanity which can only come into being through the efficacy of the Holy Spirit. For the Holy Spirit is like unto the life in the human body, which blends all differences of parts and members in unity and agreement. Consider how numerous are these parts and members, but the oneness of the animating spirit of life unites them all in perfect combination. It establishes such a unity in the bodily organism that if any part is subjected to injury or becomes diseased, all the other parts and functions sympathetically respond and suffer, owing to the perfect oneness existing. Just as the human spirit of life is the cause of coordination among the various parts of the human organism, the Holy Spirit is the controlling cause of the unity and coordination of mankind. That is to say, the bond or oneness of humanity cannot be effectively established save through the power of the Holy Spirit, for the world of humanity is a composite body, and the Holy Spirit is the animating principle of its life.
Therefore, we must strive in order that the power of the Holy Spirit may become effective throughout the world of mankind, that it may confer a new quickening life upon the body politic of the nations and peoples and that all may be guided to the protection and shelter of the Word of God. Then this human world will become angelic, earthly darkness pass away and celestial illumination flood the horizons, human defects be effaced and divine virtues become resplendent. This is possible and real, but only through the power of the Holy Spirit.
── ʻAbdu’l-Bahá, The Promulgation of Universal Peace 9/16/1912 ──