Hindu scriptures describe ultimate reality as Brahman. Brahman is non-dual pure consciousness, indivisible, incorporeal, infinite, and all-pervading like the sky. Brahman is of the nature of existence-knowledge-bliss-absolute-the ground of all existence, basis of all awareness, and source of all bliss. It is the reality of all realities, the soul of all souls, one without a second, the constant witness of the changing phenomena of the universe. From the absolute point of view, Brahman alone exists. Brahman has two aspects: transcendent and immanent. In Its transcendent aspect, Brahman is devoid of name and form, sex and attributes. But in Its immanent aspect, Brahman is endowed with them. The Upanishads designate the transcendent Brahman by the word "It" and the immanent Brahman by the word "He." Through Its inscrutable power called maya, the transcendent Brahman appears to be conditioned by time and space and to manifest itself as personal God, the creator, preserver, and destroyer of the universe. The Upanishads describe God as the supreme person:
His hands and feet are everywhere; His eyes, heads, and faces are everywhere; His ears are everywhere; He exists compassing all. The heavens are His head; the sun and moon, His eyes; the quarters, His ears; the revealed Vedas, His speech; the wind is His breath; the universe, His heart. From His feet is produced the earth. He is, indeed, the inner Self of all beings.
The various Godheads of Hinduism, such as Shiva, Vishnu, Brahma, Kali, and Durga, are but different facets of Brahman. The supreme Brahman assumes various forms for the fulfillment of the individual spiritual seekers. All concepts and forms of God, according to Hinduism, are what we think of Him and not what He is to Himself. Again, various seekers of God, depending upon their advancement, perceive God differently. For example, to the beginner God appears as an extra-cosmic creator; to the more advanced seeker as inner controller; and to the perfect knower of God, God is everywhere and in everything. Still another manifestation of the conditioned Brahman is the incarnation of God-God's taking human form. According to Hinduism, God incarnates Himself to fulfill the needs of the universe, whenever and wherever such a need arises. In the Bhagavad Gita Sri Krishna says:
Whenever there is a decline of dharma (righteousness), O Bharata, and a rise of adharma (unrighteousness), I incarnate myself. For the protection of the good, for the destruction of the wicked, and for the establishment of dharma, I am born in every age.
Thus, according to Hinduism, the supreme Godhead is both formless and endowed with many forms.