God is Infinite and Beyond Comprehension:
God is infinite; the works of God are infinite; the bestowals of God are infinite.
(`Abdu’l-Baha: Promulgation of Universal Peace, p. 159)

The purport of this is that God is almighty, but His greatness cannot be brought within the grasp of human limitation. We cannot limit God to a boundary. Man is limited, but the world of Divinity is unlimited. Prescribing limitation to God is human ignorance. God is the Ancient, the Almighty; His attributes are infinite. He is God because His light, His sovereignty, is infinite.
(`Abdu’l-Baha: Promulgation of Universal Peace, p. 274)

Nevertheless, we speak of the names and attributes of the Divine Reality, and we praise Him by attributing to Him sight, hearing, power, life and knowledge. We affirm these names and attributes, not to prove the perfections of God, but to deny that He is capable of imperfections. When we look at the existing world, we see that ignorance is imperfection and knowledge is perfection; therefore, we say that the sanctified Essence of God is wisdom. Weakness is imperfection, and power is perfection; consequently, we say that the sanctified Essence of God is the acme of power. It is not that we can comprehend His knowledge, His sight, His power and life, for it is beyond our comprehension; for the essential names and attributes of God are identical with His Essence, and His Essence is above all comprehension.
(`Abdu’l-Baha: Some Answered Questions, p. 148)

Existence is of two kinds: one is the existence of God which is beyond the comprehension of man. He, the invisible, the lofty and the incomprehensible, is preceded by no cause but rather is the Originator of the cause of causes. He, the Ancient, hath had no beginning and is the all-independent.
(`Abdu’l-Baha: Selections … `Abdu’l-Baha, p. 61)

God is Supreme Over All Creation:
How wondrous is the unity of the Living, the Ever-Abiding God – a unity which is exalted above all limitations, that transcendeth the comprehension of all created things! He hath, from everlasting, dwelt in His inaccessible habitation of holiness and glory, and will unto everlasting continue to be enthroned upon the heights of His independent sovereignty and grandeur. How lofty hath been His incorruptible Essence, how completely independent of the knowledge of all created things, and how immensely exalted will it remain above the praise of all the inhabitants of the heavens and the earth!
(Baha’u’llah: Gleanings, pp. 261-262)

Thou art He Whom all things worship and Who worshipeth no one, Who is the Lord of all things and is the vassal of none, Who knoweth all things and is known of none. Thou didst wish to make Thyself known unto men; therefore, Thou didst, through a word of Thy mouth, bring creation into being and fashion the universe.
(Baha’u’llah: Prayers and Meditations, p. 6)

Thou art the God Who hath existed before all things, Who will exist after all things and will last beyond all things. Thou art the God Who knoweth all things, and is supreme over all things. Thou art the God Who dealeth mercifully with all things, Who judgeth between all things and Whose vision embraceth all things.
(The Bab: Selections from the Bab, p. 186)

God testifieth that there is none other God but Him. His are the kingdoms in the heavens and on the earth and all that is between them. He is exalted above the comprehension of all things, and is inscrutable to the mind of every created being; none shall be able to fathom the oneness of His Being or to unravel the nature of His Existence. No peer or likeness, no similitude or equal can ever be joined with Him.
(The Bab: Selections from the Bab, p. 154)

God is Known Through Manifestations of God:
These Prophets and chosen Ones of God are the recipients and revealers of all the unchangeable attributes and names of God. They are the mirrors that truly and faithfully reflect the light of God. Whatsoever is applicable to them is in reality applicable to God, Himself, Who is both the Visible and the Invisible.
(Baha’u’llah: The Kitab-i-Iqan, p. 142)

Nay rather, the attribute of sovereignty and all other names and attributes of God have been and will ever be vouchsafed unto all the Manifestations of God, before and after Him, inasmuch as these Manifestations, as it hath already been explained, are the Embodiments of the attributes of God, the Invisible, and the Revealers of the divine mysteries.
(Baha’u’llah: The Kitab-i-Iqan, p. 107)

The knowledge of the Reality of the Divinity is impossible and unattainable, but the knowledge of the Manifestations of God is the knowledge of God, for the bounties, splendors and divine attributes are apparent in Them. Therefore, if man attains to the knowledge of the Manifestations of God, he will attain to the knowledge of God; and if he be neglectful of the knowledge of the Holy Manifestations, he will be bereft of the knowledge of God.
(`Abdu’l-Baha: Some Answered Questions, p. 222)

God is Known Through Creation:
Nay, whatever is in the heavens and whatever is on the earth is a direct evidence of the revelation within it of the attributes and names of God, inasmuch as within every atom are enshrined the signs that bear eloquent testimony to the revelation of that most great Light.
(Baha’u’llah: The Kitab-i-Iqan, p. 100)

From that which hath been said it becometh evident that all things, in their inmost reality, testify to the revelation of the names and attributes of God within them. Each according to its capacity, indicateth, and is expressive of, the knowledge of God. So potent and universal is this revelation, that it hath encompassed all things, visible and invisible.
(Baha’u’llah: The Kitab-i-Iqan, p. 102)

How shall we know God? We know Him by His attributes. We know Him by His signs. We know Him by His names. We know not what the reality of the sun is, but we know the sun by the ray, by the heat, by its efficacy and penetration. We recognize the sun by its bounty and effulgence, but as to what constitutes the reality of the solar energy, that is unknowable to us. The attributes characterizing the sun, however, are knowable. If we wish to come in touch with the reality of Divinity, we do so by recognizing its phenomena, its attributes and traces, which are widespread in the universe. All things in the world of phenomena are expressive of that one reality. Its lights are shining, its heat is manifest, its power is expressive, and its education, or training, resplendent everywhere.
(`Abdu’l-Baha: Promulgation of Universal Peace, p. 422)