The Baha’i writings say we cannot know God directly, because He is so far above our understanding. In one of Baha’u’llah’s most mystical prayers, he addresses this powerful theme:
I cannot think, O my God, of any words wherewith to make mention of Thee, and know not how to express or extol Thee. Were I to attempt to describe Thee by Thy names, I would readily recognize that the kingdom of these names is itself created through the movement of Thy fingers, and trembleth for fear of Thee. And were I to venture to extol Thine attributes, I would be forced to admit that these attributes are Thine own creation, and lie within Thy grasp. It behooveth not Them Who are the Manifestations of these names and attributes to stand before the gate of the city of Thy Revelation, how much less to scale the heights whereon Thou didst stablish the throne of Thy majesty.
I swear by Thy might, O Thou Who art the King of names and the Maker of the heavens! Whatsoever hath been adorned with the robe of words is but Thy creation which hath been generated in Thy realm and begotten through the operation of Thy will, and is wholly unworthy of Thy highness and falleth short of Thine excellence.
And since it hath been demonstrated that Thy most august Self is immeasurably exalted above all that hath been created in the world of being, and is far above the reach and ken of the apprehension of Thy chosen Ones and Thy loved Ones, the splendors of the light of Thy unity are therefore manifested, and it becometh evident unto every one, whether free or bond, that Thou art One in Thine own Self, one in Thy Cause, and one in Thy Revelation. Great is the blessedness of the man who, in his love towards Thee, hath rid himself of all attachment from every one except Thyself, and hastened unto the horizon of Thy Revelation, and attained unto this Cup which Thou hast caused to excel all the seas of the earth. – Baha’u’llah, Prayers and Meditations by Baha’u’llah, pp. 273-275.
For this reason God manifests Himself to us through His prophets:
The door of the knowledge of the Ancient of Days being thus closed in the face of all beings, the Source of infinite grace, according to His saying, “His grace hath transcended all things; My grace hath encompassed them all,” hath caused those luminous Gems of Holiness to appear out of the realm of the spirit, in the noble form of the human temple, and be made manifest unto all men, that they may impart unto the world the mysteries of the unchangeable Being, and tell of the subtleties of His imperishable Essence.
These sanctified Mirrors, these Day Springs of ancient glory, are, one and all, the Exponents on earth of Him Who is the central Orb of the universe, its Essence and ultimate Purpose. From Him proceed their knowledge and power; from Him is derived their sovereignty. The beauty of their countenance is but a reflection of His image, and their revelation a sign of His deathless glory. They are the Treasuries of Divine knowledge, and the Repositories of celestial wisdom. Through them is transmitted a grace that is infinite, and by them is revealed the Light that can never fade…
These Tabernacles of Holiness, these Primal Mirrors which reflect the light of unfading glory, are but expressions of Him Who is the Invisible of the Invisibles. By the revelation of these Gems of Divine virtue all the names and attributes of God, such as knowledge and power, sovereignty and dominion, mercy and wisdom, glory, bounty, and grace, are made manifest. – Baha’u’llah, Gleanings from the Writings of Baha’u’llah, pp. 47-48.
Baha’is do not believe that the messengers, prophets and manifestations of God are equal to Him. They are not God incarnate–for God is far too exalted ever to incarnate His Essence. Rather, the prophets are like perfect mirrors reflecting God’s attributes. They are the revealers of His Word. In that sense, to know them is to know God. Their purpose: to educate and uplift the souls, to guide our social and spiritual evolution, and to show us the way to eternal life. In each age they appear, revealing laws and teachings appropriate for that time:
Men at all times and under all conditions stand in need of one to exhort them, guide them and to instruct and teach them. Therefore He hath sent forth His Messengers, His Prophets and chosen ones that they might acquaint the people with the divine purpose underlying the revelation of Books and the raising up of Messengers, and that everyone may become aware of the trust of God which is latent in the reality of every soul. – ibid, p. 161.