Written in the midst of the Second World War, Shoghi Effendi explained and clarified the significance of that crisis, from where it emerged and to what it would ultimately lead.

The Promised Day is Come can be read in full at the Bahá’í Reference Library. Some extracts are shared below.

A tempest, unprecedented in its violence, unpredictable in its course, catastrophic in its immediate effects, unimaginably glorious in its ultimate consequences, is at present sweeping the face of the earth. Its driving power is remorselessly gaining in range and momentum. Its cleansing force, however much undetected, is increasing with every passing day. Humanity, gripped in the clutches of its devastating power, is smitten by the evidences of its resistless fury. It can neither perceive its origin, nor probe its significance, nor discern its outcome. Bewildered, agonized and helpless, it watches this great and mighty wind of God invading the remotest and fairest regions of the earth, rocking its foundations, deranging its equilibrium, sundering its nations, disrupting the homes of its peoples, wasting its cities, driving into exile its kings, pulling down its bulwarks, uprooting its institutions, dimming its light, and harrowing up the souls of its inhabitants.

Dear friends! The powerful operations of this titanic upheaval are comprehensible to none except such as have recognized the claims of both Bahá’u’lláh and the Báb. Their followers know full well whence it comes, and what it will ultimately lead to. Though ignorant of how far it will reach, they clearly recognize its genesis, are aware of its direction, acknowledge its necessity, observe confidently its mysterious processes, ardently pray for the mitigation of its severity, intelligently labor to assuage its fury, and anticipate, with undimmed vision, the consummation of the fears and the hopes it must necessarily engender.

We are indeed living in an age which, if we would correctly appraise it, should be regarded as one which is witnessing a dual phenomenon. The first signalizes the death pangs of an order, effete and godless, that has stubbornly refused, despite the signs and portents of a century-old Revelation, to attune its processes to the precepts and ideals which that Heaven-sent Faith proffered it. The second proclaims the birth pangs of an Order, divine and redemptive, that will inevitably supplant the former, and within Whose administrative structure an embryonic civilization, incomparable and world-embracing, is imperceptibly maturing. The one is being rolled up, and is crashing in oppression, bloodshed, and ruin. The other opens up vistas of a justice, a unity, a peace, a culture, such as no age has ever seen. The former has spent its force, demonstrated its falsity and barrenness, lost irretrievably its opportunity, and is hurrying to its doom. The latter, virile and unconquerable, is plucking asunder its chains, and is vindicating its title to be the one refuge within which a sore-tried humanity, purged from its dross, can attain its destiny.

The Faith standing identified with the name of Bahá’u’lláh disclaims any intention to belittle any of the Prophets gone before Him, to whittle down any of their teachings, to obscure, however slightly, the radiance of their Revelations, to oust them from the hearts of their followers, to abrogate the fundamentals of their doctrines, to discard any of their revealed Books, or to suppress the legitimate aspirations of their adherents. Repudiating the claim of any religion to be the final revelation of God to man, disclaiming finality for His own Revelation, Bahá’u’lláh inculcates the basic principle of the relativity of religious truth, the continuity of Divine Revelation, the progressiveness of religious experience. His aim is to widen the basis of all revealed religions and to unravel the mysteries of their scriptures. He insists on the unqualified recognition of the unity of their purpose, restates the eternal verities they enshrine, coordinates their functions, distinguishes the essential and the authentic from the nonessential and spurious in their teachings, separates the God-given truths from the priest-prompted superstitions, and on this as a basis proclaims the possibility, and even prophecies the inevitability, of their unification, and the consummation of their highest hopes.

This vital force is dying out, this mighty agency has been scorned, this radiant light obscured, this impregnable stronghold abandoned, this beauteous robe discarded. God Himself has indeed been dethroned from the hearts of men, and an idolatrous world passionately and clamorously hails and worships the false gods which its own idle fancies have fatuously created, and its misguided hands so impiously exalted. The chief idols in the desecrated temple of mankind are none other than the triple gods of Nationalism, Racialism and Communism, at whose altars governments and peoples, whether democratic or totalitarian, at peace or at war, of the East or of the West, Christian or Islamic, are, in various forms and in different degrees, now worshiping. Their high priests are the politicians and the worldly-wise, the so-called sages of the age; their sacrifice, the flesh and blood of the slaughtered multitudes; their incantations outworn shibboleths and insidious and irreverent formulas; their incense, the smoke of anguish that ascends from the lacerated hearts of the bereaved, the maimed, and the homeless.

The theories and policies, so unsound, so pernicious, which deify the state and exalt the nation above mankind, which seek to subordinate the sister races of the world to one single race, which discriminate between the black and the white, and which tolerate the dominance of one privileged class over all others—these are the dark, the false, and crooked doctrines for which any man or people who believes in them, or acts upon them, must, sooner or later, incur the wrath and chastisement of God.

“Movements,” is the warning sounded by ‘Abdu’l-Bahá, “newly born and worldwide in their range, will exert their utmost effort for the advancement of their designs. The Movement of the Left will acquire great importance. Its influence will spread.”

Contrasting with, and irreconcilably opposed to, these war-engendering, world-convulsing doctrines are the healing, the saving, the pregnant truths proclaimed by Bahá’u’lláh, the Divine Organizer and Savior of the whole human race—truths which should be regarded as the animating force and the hallmark of His Revelation: “The world is but one country, and mankind its citizens.” “Let not a man glory in that he loves his country; let him rather glory in this, that he loves his kind.” And again: “Ye are the fruits of one tree, and the leaves of one branch.” “Bend your minds and wills to the education of the peoples and kindreds of the earth, that haply … all mankind may become the upholders of one order, and the inhabitants of one city…. Ye dwell in one world, and have been created through the operation of one Will.” “Beware lest the desires of the flesh and of a corrupt inclination provoke divisions among you. Be ye as the fingers of one hand, the members of one body.” And yet again: “All the saplings of the world have appeared from one Tree, and all the drops from one Ocean, and all beings owe their existence to one Being.” And furthermore: “That one indeed is a man who today dedicateth himself to the service of the entire human race.”

God’s purpose is none other than to usher in, in ways He alone can bring about, and the full significance of which He alone can fathom, the Great, the Golden Age of a long-divided, a long-afflicted humanity. Its present state, indeed even its immediate future, is dark, distressingly dark. Its distant future, however, is radiant, gloriously radiant—so radiant that no eye can visualize it.

“The winds of despair,” writes Bahá’u’lláh, as He surveys the immediate destinies of mankind, “are, alas, blowing from every direction, and the strife that divides and afflicts the human race is daily increasing. The signs of impending convulsions and chaos can now be discerned, inasmuch as the prevailing order appears to be lamentably defective.” “Such shall be its plight,” He, in another connection, has declared, “that to disclose it now would not be meet and seemly.” “These fruitless strifes,” He, on the other hand, contemplating the future of mankind, has emphatically prophesied, in the course of His memorable interview with the Persian orientalist, Edward G. Browne, “these ruinous wars shall pass away, and the ‘Most Great Peace’ shall come…. These strifes and this bloodshed and discord must cease, and all men be as one kindred and one family.” “Soon,” He predicts, “will the present-day order be rolled up, and a new one spread out in its stead.” “After a time,” He also has written, “all the governments on earth will change. Oppression will envelop the world. And following a universal convulsion, the sun of justice will rise from the horizon of the unseen realm.” “The whole earth,” He, moreover, has stated, “is now in a state of pregnancy. The day is approaching when it will have yielded its noblest fruits, when from it will have sprung forth the loftiest trees, the most enchanting blossoms, the most heavenly blessings.” “All nations and kindreds,” ‘Abdu’l-Bahá likewise has written, “…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.”

What we witness at the present time, during “this gravest crisis in the history of civilization,” recalling such times in which “religions have perished and are born,” is the adolescent stage in the slow and painful evolution of humanity, preparatory to the attainment of the stage of manhood, the stage of maturity, the promise of which is embedded in the teachings, and enshrined in the prophecies, of Bahá’u’lláh. The tumult of this age of transition is characteristic of the impetuosity and irrational instincts of youth, its follies, its prodigality, its pride, its self-assurance, its rebelliousness, and contempt of discipline.

The world is, in truth, moving on towards its destiny. The interdependence of the peoples and nations of the earth, whatever the leaders of the divisive forces of the world may say or do, is already an accomplished fact. Its unity in the economic sphere is now understood and recognized. The welfare of the part means the welfare of the whole, and the distress of the part brings distress to the whole. The Revelation of Bahá’u’lláh has, in His own words, “lent a fresh impulse and set a new direction” to this vast process now operating in the world. The fires lit by this great ordeal are the consequences of men’s failure to recognize it. They are, moreover, hastening its consummation. Adversity, prolonged, worldwide, afflictive, allied to chaos and universal destruction, must needs convulse the nations, stir the conscience of the world, disillusion the masses, precipitate a radical change in the very conception of society, and coalesce ultimately the disjointed, the bleeding limbs of mankind into one body, single, organically united, and indivisible.