This principle existed when neither the gods, nor people, nor anything other being of creation existed. This is the One and Only cause of everything- the One and Only God, Who in Sanskrit is called "Brahman.
Vedic statements like "Ekam sad vipra bahudha vadanti" ("One alone exists, sages call It by various names."), not only emphasize the oneness of God, but display the tolerance of Hinduism. The concept of harmony in religions is a fundamental ingredient in the Vedas.
If you were to ask me, "Who was here before creation?" the Hindu reply is that the only Creator, or God, was here. However, if you ask, "What was God like before creation?" Hinduism's reply is that God was in a transcendental state of existence. This means that God's existence was beyond our conceptions of time, space, and causation. Hinduism teaches that when God created the world, he also at that time created time and space. God in this transcendental state is "Nirguna Brahman." ( "the Supreme Spirit," "the Impersonal and Attributeless God.") Since personality is a limitation, Nirguna Brahman cannot and does not have one. It possesses no sex. Neither pronouns "He," nor "She," can be used to refer to God at this point. The Vedas use the Sanskrit pronoun "Tat," which is equal to the English "That," to refer to Nirguna Brahman. Also, the HIndu expressions "Absolute Truth," "Consciousness," and "Infinite Bliss," are synonymous with Nirguna Brahman. No matter which of the expressions are used, Nirguna Brahman can never be adequately described by the limited adjectives of our world.
As men began to think of the limitless Nirguna Brahman with their limited minds, they projected their limitations upon It. The impersonal God acquired a personality which resembled that of a human. Nirguna Brahman appeared to become "Saguna Brahman" or "Ishvara" ("Personal God"). Please know that Nirguna Brahman did not undergo any kind of alteration at this period.