All the “meanings, perfection, and qualities” of previous Manifestations of God are now manifested in Baha’u’llah

“In the Book of the Zend-Avesta the Zoroastrians are awaiting the Coming of two Manifestations. Also, in the Old Testament Scriptures there is the promise of Elijah and Messiah. In the Gospel of the New Testament they are expecting the Father and the Second Coming of Christ. Likewise, in the Qur'án the Muhammadans have the promise of the Imám Mihdí and Christ. In brief, all the Holy Scriptures announce the Coming of two Manifestations, and these two Manifestations are the Báb and the Blessed Perfection. If you look into the Bible, it is Elias and Christ; in the Qur'án it is the Mihdí and Christ. These tidings are the same in all the Holy Books, only expressed in different ways -- two successive Manifestations. And all the Universe is promised these two. We must not search for the outer word in Elijah and Christ but look for the Reality. The Blessed Perfection said in His Tablets that once He was Abraham, once Moses, once Jesus, once Muhammad, and once the Báb. This is explained clearly in the 'Book of Íqán,' that is, the meanings and perfection of qualities which were once hidden are now revealed in Bahá‘u’lláh. Therefore, we can consider Bahá‘u’lláh to be all the Prophets, no matter by what Name He chooses to call Himself; for all their meanings, perfection, and qualities are manifest in Him. Bahá‘u’lláh is the center of all their perfections. For instance, in Moses the world received the Revelation of material laws, in Jesus spiritual laws, while in Bahá‘u’lláh we have received both material and spiritual laws. The Laws of Moses would cover but few pages, and the Teachings of Jesus could be gathered into a small pamphlet. The Old Testament contains nothing but material laws; no mention is in it of spiritual laws such as we find in the New Testament. In the New Testament there are no material laws except the laws of divorce and of the Sabbath. The New Testament contains no answers to questions of science. But all knowledge has been revealed by the Blessed Perfection in books which if gathered together would make many volumes. He has revealed demonstrations in sciences, and He is the epitome of all previous Revelations.” (‘Abdu’l-Baha, a table talk recorded by Julia M. Grundy in 1905, ‘Ten Days In the Light of ‘Akka’, Baha’i Publishing Trust, Wilmette, Ill., 1979)