To the ordinary man living in this world, external phenomena, which he perceives with his senses, constitute the only reality. So far as he is concerned God, whom he cannot see or hear, is just a word. As he progresses in rational thinking and evolves spiritually he realizes that the world-phenomena that he sees around him are always in a flux and therefore, being impermanent, cannot be the ultimate Reality. So he may consider this world as something in explicable or indefinable. But when one reaches the highest level of philosophical contemplation and spiritual evolution one realizes that this phenomenal world is real only in a relative sense. God is the only true Reality; everything else is ephemeral.
The Vedic literature reveals the origin, progress and culmination of man’s concept of God or the ultimate Reality: from polytheism to monotheism and from monotheism to monism; from the many with names and forms to the one impersonal Reality that is beyond name and form.
The Rig Vedic concept of the ultimate Reality is unique. It has monistic as well as dualistic components. The whole process of creation and evolution of nature (from a primeval state) is ex pressed in mythological language in the Rig Veda. Parallel to the evolution of the concept of Reality, we can also see the progress of the concept of God.
The Vedic mind is seen to progress from prayers for long and happy life to lofty idealism. Sometimes, it is asserted that the Reality behind the fire principle is one; the same Truth is behind the sun which illumines the universe; the same Reality underlies Ushas which makes everything effulgent, and so on.
Agni is one though ignited in various forms, the one sun rises in all the worlds, the one dawn lights up all this; the One alone has become all this. (Rig Veda 8.58.2)
Swami Bhoomananda Tirtha Quotes