Behold the disturbances which, for many a long year, have afflicted the earth, and the perturbation that hath seized its peoples. It hath either been ravaged by war, or tormented by sudden and unforeseen calamities.

Bahá’u’lláh, Tablets of Bahá’u’lláh, p.163

Beware lest ye shed the blood of anyone. Unsheathe the sword of your tongue from the scabbard of utterance, for therewith ye can conquer the citadels of men’s hearts. We have abolished the law to wage holy war against each other. God’s mercy, hath, verily, encompassed all created things, if ye do but understand. Aid ye your Lord, the God of Mercy, with the sword of understanding. Keener indeed is it, and more finely tempered, than the sword of utterance, were ye but to reflect upon the words of your Lord. Thus have the hosts of Divine Revelation been sent down by God, the Help in Peril, the Self-Subsisting, and thus have the armies of divine inspiration been made manifest from the Source of command, as bidden by God, the All-Glorious, the Best-Beloved.

Bahá’u’lláh, Epistle to the Son of the Wolf, p. 25

The time must come when the imperative necessity for the holding of a vast, an all-embracing assemblage of men will be universally realized. The rulers and kings of the earth must needs attend it, and, participating in its deliberations, must consider such ways and means as will lay the foundations of the world's Great Peace amongst men. Such a peace demandeth that the Great Powers should resolve, for the sake of the tranquillity of the peoples of the earth, to be fully reconciled among themselves. Should any king take up arms against another, all should unitedly arise and prevent him. If this be done, the nations of the world will no longer require any armaments, except for the purpose of preserving the security of their realms and of maintaining internal order within their territories. This will ensure the peace and composure of every people, government and nation.

Bahá’u’lláh, Gleanings from the Writings of Bahá’u’lláh, p. 248

Bahá’u’lláh has proclaimed and promulgated the foundation of international peace. For thousands of years men and nations have gone forth to the battlefield to settle their differences. The cause of this has been ignorance and degeneracy. Praise be to God! In this radiant century minds have developed, perceptions have become keener, eyes are illumined and ears attentive. Therefore, it will be impossible for war to continue. Consider human ignorance and inconsistency. A man who kills another man is punished by execution, but a military genius who kills one hundred thousand of his fellow creatures is immortalized as a hero. One man steals a small sum of money and is imprisoned as a thief. Another pillages a whole country and is honored as a patriot and conqueror. A single falsehood brings reproach and censure, but the wiles of politicians and diplomats excite the admiration and praise of a nation. Consider the ignorance and inconsistency of mankind. How darkened and savage are the instincts of humanity!

‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 287

But war is made for the satisfaction of men's ambition; for the sake of worldly gain to the few, terrible misery is brought to numberless homes, breaking the hearts of hundreds of men and women! How many widows mourn their husbands, how many stories of savage cruelty do we hear! How many little orphaned children are crying for their dead fathers, how many women are weeping for their slain sons! There is nothing so heart-breaking and terrible as an outburst of human savagery!

‘Abdu’l-Bahá, Paris Talks, p. 29

Consider that there are two hundred and fifty million Christians and three hundred million Muslims. How much blood has flowed in their wars; how many nations have been destroyed; how many children have been made fatherless; how many fathers and mothers have mourned the loss of children and dear ones! All this has been due to prejudice, misunderstanding and imitations of ancestral beliefs without investigation of reality.

‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 201