Nature of Baha'u'llah
Greetiings, Brian.
I have only just discovered this site and have been strolling around a bit. I love your questions and attitude, and think you are an excellent administrator! Keep up the good work!
As to the nature of Baha'u'llah -- this is absolutely central to understanding Baha'i belief. I hope you will not mind an extensive quote in Baha'u'llah's own words. (I have edited a bit - indicated by " .... " to shorten it and make reading easier.) Entire text:
http://bahai-library.com/writings/bahaullah/gwb/022.html
I think it is best to start there, and add our personal explanations and explorations of the ideas afterwards.
Gleanings from the Writings of Baha'u'llah XXII: The Bearers of the Trust of God are made manifest ...
1 The Bearers of the Trust of God are made manifest unto the peoples of the earth as the Exponents of a new Cause and the Revealers of a new Message. Inasmuch as these Birds of the celestial Throne are all sent down from the heaven of the Will of God, and as they all arise to proclaim His irresistible Faith, they, therefore, are regarded as one soul and the same person. For they all drink from the one Cup of the love of God, and all partake of the fruit of the same Tree of Oneness.
2 These Manifestations of God have each a twofold station. One is the station of pure abstraction and essential unity. In this respect, if thou callest them all by one name, and dost ascribe to them the same attributes, thou hast not erred from the truth. ... For they, one and all, summon the people of the earth to acknowledge the unity of God, and herald unto them the Kawthar of an infinite grace and bounty. They are all invested with the robe of prophethood, and are honored with the mantle of glory. Thus hath Muhammad, the Point of the Qur'án, revealed: "I am all the Prophets." ...
3 It is clear and evident to thee that all the Prophets are the Temples of the Cause of God, Who have appeared clothed in divers attire. If thou wilt observe with discriminating eyes, thou wilt behold Them all abiding in the same tabernacle, soaring in the same heaven, seated upon the same throne, uttering the same speech, and proclaiming the same Faith. Such is the unity of those Essences of Being, those Luminaries of infinite and immeasurable splendor! Wherefore, should one of these Manifestations of Holiness proclaim saying: "I am the return of all the Prophets," He, verily, speaketh the truth. In like manner, in every subsequent Revelation, the return of the former Revelation is a fact, the truth of which is firmly established ....
4 The other station is the station of distinction, and pertaineth to the world of creation, and to the limitations thereof. In this respect, each Manifestation of God hath a distinct individuality, a definitely prescribed mission, a predestined revelation, and specially designated limitations. Each one of them is known by a different name, is characterized by a special attribute, fulfils a definite mission, and is entrusted with a particular Revelation. ...
5 It is because of this difference in their station and mission that the words and utterances flowing from these Well Springs of Divine knowledge appear to diverge and differ. Otherwise, in the eyes of them that are initiated into the mysteries of Divine wisdom, all their utterances are, in reality, but the expressions of one Truth. As most of the people have failed to appreciate those stations to which We have referred, they, therefore, feel perplexed and dismayed at the varying utterances pronounced by Manifestations that are essentially one and the same.
6 ... Thus, viewed from the standpoint of their oneness and sublime detachment, the attributes of Godhead, Divinity, Supreme Singleness, and Inmost Essence, have been, and are applicable to those Essences of Being, inasmuch as they all abide on the throne of Divine Revelation, and are established upon the seat of Divine Concealment. Through their appearance the Revelation of God is made manifest, and by their countenance the Beauty of God is revealed. Thus it is that the accents of God Himself have been heard uttered by these Manifestations of the Divine Being.
7 Viewed in the light of their second station ñ the station of distinction, differentiation, temporal limitations, characteristics and standards ñ they manifest absolute servitude, utter destitution, and complete self-effacement. Even as He saith: "I am the servant of God. I am but a man like you."...
8 Were any of the all-embracing Manifestations of God to declare: "I am God," He, verily, speaketh the truth, and no doubt attacheth thereto. For it hath been repeatedly demonstrated that through their Revelation, their attributes and names, the Revelation of God, His names and His attributes, are made manifest in the world. ... And were any of them to voice the utterance, "I am the Messenger of God," He, also, speaketh the truth, the indubitable truth. ... Viewed in this light, they are all but Messengers of that ideal King, that unchangeable Essence. And were they all to proclaim, "I am the Seal of the Prophets," they, verily, utter but the truth, beyond the faintest shadow of doubt. For they are all but one person, one soul, one spirit, one being, one revelation. They are all the manifestation of the "Beginning" and the "End," the "First" and the "Last," the "Seen" and the "Hidden" ñ all of which pertain to Him Who is the Innermost Spirit of Spirits and Eternal Essence of Essences. And were they to say, "We are the Servants of God," this also is a manifest and indisputable fact. For they have been made manifest in the uttermost state of servitude, a servitude the like of which no man can possibly attain. ...
9 Were the eye of discernment to be opened, it would recognize that in this very state, they have considered themselves utterly effaced and non-existent in the face of Him Who is the All-Pervading, the Incorruptible. Methinks, they have regarded themselves as utter nothingness, and deemed their mention in that Court an act of blasphemy. For the slightest whispering of self within such a Court is an evidence of self-assertion and independent existence. In the eyes of them that have attained unto that Court, such a suggestion is itself a grievous transgression. ....
10 By virtue of this station they have claimed for themselves the Voice of Divinity and the like, whilst by virtue of their station of Messengership, they have declared themselves the Messengers of God. In every instance they have voiced an utterance that would conform to the requirements of the occasion, and have ascribed all these declarations to Themselves, declarations ranging from the realm of Divine Revelation to the realm of creation, and from the domain of Divinity even unto the domain of earthly existence. Thus it is that whatsoever be their utterance, whether it pertain to the realm of Divinity, Lordship, Prophethood, Messengership, Guardianship, Apostleship, or Servitude, all is true, beyond the shadow of a doubt. ...