be regarded as physicians whose task is to foster the well-being of the world and its peoples… Little wonder, then, if the treatment prescribed by the physician in this day should not be found to be identical with that which he prescribed before. How could it be otherwise when the ills affecting the sufferer necessitate at every stage of his sickness a special remedy? In like manner, every time the Prophets of God have illumined the world with the resplendent radiance of the Day Star of Divine knowledge, they have invariably summoned its peoples to embrace the light of God through such means as best befitted the exigencies of the age in which they appeared." Bahá’ís perceive each major world religion as part of one God-ordained holistic educational process which has spiritually and socially enabled human civilization itself to progress—as people have learned to embrace ever-widening circles of unity which have successively involved ever more diverse families, tribes, city-states, and then nations. Inevitably, the human race must, and will, embrace its final circle of unity, that of the planet itself. Bahá’u’lláh links this "process of progressive Revelation" to God’s eternal covenant—the promise that every divine teacher makes with his followers regarding the next manifestation whom the Creator will send to guide them. Prophecies pertaining to this great covenant are found in scriptures of all religions, with every manifestation prophesying about the next one, and even others, to come. As for their responsibility in this covenant, the followers of each religion have the duty to carefully investigate, with an open mind, whether a person claiming to be the promised new messenger of their faith does, or does not, spiritually fulfill relevant prophecies. Claims of prophetic fulfillment In announcing his claim to be the promised manifestation heralded by the Báb, Baháʼu'lláh also declared his station as the Promised One prophesied in every major religion of the past—the divine teacher God vowed to send to usher in humanity's Golden Age. Bahá’u’lláh’s claim to being several 'messiahs' converging in one person is understood by Bahá’ís as being a spiritual symbolic fulfillment rather than a literal fulfilment of messianic and eschatological prophecies of past faiths. This understanding is based upon Bahá’u’lláh’s teachings regarding the oneness of God's manifestations, and the essential oneness of religion. Thus, Bahá’ís see Bahá’u’lláh as fulfilling prophecies for Jews as the incarnation of the "Everlasting Father", the "Lord of Hosts", and