It is evident unto thee that the Birds of Heaven and Doves of Eternity speak a twofold language. One language, the outward language, is devoid of allusions, is unconcealed and unveiled; that it may be a guiding lamp and a beaconing light whereby wayfarers may attain the heights of holiness, and seekers may advance into the realm of eternal reunion. Such are the unveiled traditions and the evident verses already mentioned. The other language is veiled and concealed, so that whatever lieth hidden in the heart of the malevolent may be made manifest and their innermost being be disclosed... This is the divine standard, this is the Touchstone of God, wherewith He proveth His servants. None apprehendeth the meaning of these utterances except them whose hearts are assured, whose souls have found favour with God, and whose minds are detached from all else but Him. In such utterances, the literal meaning, as generally understood by the people, is not what hath been intended...
These things We mention only that the people may not be dismayed because of certain traditions and utterances, which have not yet been literally fulfilled, that they may rather attribute their perplexity to their own lack of understanding, and not to the non-fulfilment of the promises in the traditions... The people, therefore, must not allow such utterances to deprive them of the divine bounties, but should rather seek enlightenment from them who are the recognized Expounders thereof, so that the hidden mysteries may be unravelled, and be made manifest unto them.
One of Baha'u'llah's major challenges was to explain, given that he was claiming to be the fulfillment of the prophecies of various religions, how it was that the events contained in these prophecies did not appear to have occurred. Primarily in his book Kitab-i-Iqan (The Book of Certitude), but also in other works, he explains that the prophets of God have always been primarily concerned with the spiritual world and not with the physical one. When they have wanted to allude to great events of the future, they used metaphors to express these spiritual events. Thus, for example, the sun that is said in both the Bible and the Quran to be darkened in prophecies about the Day of Judgment refers, according to Baha'u'llah, to the fact that the sun of the previous religion is darkened by the interpretations and distortions of human beings. The light shed by the leaders of knowledge is turned to darkness when they bar their followers from recognizing the new prophet when he comes, and the laws and teaching of the previous religion, which had formerly shed light, become darkened in comparison to the new light that has appeared. In prophecies about the return of Christ or the Mahdi, the great battle, these figures fight and the victory they win refers to the spiritual battle that they must fight against the forces of darkness and their victory over these.