Sanatan Dharma, like other scientific disciplines, has always strived to find the truth underlying different aspects of life. Various scriptures of ancient India have laid down different ethical, religious and spiritual principles ; most of which are in conformity with the scientific worldview. The vastness of the cosmos described in chapter eleven of Bhagavad Gita has later been confirmed by various scientific studies. Even the Hindu concept of Avatara supports Darwin's theory of evolution as much as Lord Vishnu is said to have first incarnated himself as a fish ; then a tortoise, a boar, a man-lion and a dwarf. Only then he appeared in the human form. The ten incarnations of Vishnu cover the whole evolution of mankind. Gita has iterated that everyone is bound by sansara - the infinite cycle of birth, growth, death and rebirth.
Apart from being the most authenticated treatise on religion, philosophy and spirituality ; Bhagavad Gita can be said to be an elaborate document of advanced science. Among other truths of life and beyond ; it has discussed in detail the creation, evolution and dissolution of the universe. Gita views the world as an eternal continuity, passing through different phases of formation and cessation. It never had a beginning and never will it have an end. This concept of eternal existence is supported by various scientific theories. Sri Krishna hinted at the continuity of past, present and future in shloka 2.12 when he declared that there was never a time when all beings present there at that point in time did not exist, nor any of them shall ever cease to be. Everyone had, thus, existed in the infinite past and would continue to exist in the infinite future.
Everything comes from Brahman (the Absolute Reality which is eternal truth, consciousness and joy). Brahma, on the other hand, is said to be the god of creation, who is responsible for creating all existences. Creation and destruction of the universe is a perpetual, cyclic process. Sri Krishna has elaborated upon this cycle of creation, preservation and annihilation in shlokas from 8.17 to 8.21. It has been stated that at the beginning of Brahma’s day, all existences come into being out of the unmanifest ; and at the fall of his night, they merge again into the same unmanifest state. The beings which arise at the dawn of a cosmic day, merge when the night of Brahma arrives. The very same multitudes of beings again come into existence at the beginning of another cosmic day. So the cycle continues. It has also been enumerated that one day, and also one night, of Brahma (known as kalpa) is of thousands of ages (yugas). In other words, with the beginning of one kalpa, all entities become alive and during other kalpa, they remain dormant. They become alive again with the start of another kalpa. But beyond these manifest and unmanifest states, there is yet another unmanifest and eternal dimension ; which does not perish even when all other existences cease to be. That other unmanifest is imperishable. It is considered to be the Supreme Status. Having reached there, one is not born again. That is the supreme abode of the Divine.
The concept of cyclic creation has been re-iterated in shlokas from 9.7 to 9.10 wherein it has been stated that nature creates all beings - both animate and the inanimate - under the directions of the Supreme Lord. Presiding over His material nature, the Supreme Lord again and again creates all myriad forms, in conformity with their inherent nature. Due to such creation, the material world undergoes all changes (of creation, sustenance and dissolution). It has further been explained that at the end of one kalpa, all beings merge into the material nature of the Supreme Lord and at the start of another, He creates them again. That is why Sri Krishna says in shlokas 9.17 and 9.18 that He (the Supreme Lord) is the support, mother, father and grandfather of the entire universe. He is the origin and the dissolution of the universe - the basis of everything, the resting place and the imperishable seed.
To sum up the above paragraphs, all existences come into being out of the unmanifest and imperishable source and merge again into that very source. This cyclic activity goes on, and on and on.
Who is the unmanifest source of all existences ? This question has been answered by Sri Krishna in shloka 10.8 wherein it has been stated that He is the source of all of the creation and everything in the cosmos evolves from Him. The same thought has been repeated in shloka 9.4 in which He states that the entire creation is pervaded by Him in His unmanifest form. All living beings dwell in Him.
To conclude, God creates all embodied beings and their support systems. Creation and destruction go hand in hand. At one level formation is happening and still on other, dissolution is taking place. The temporal world so formed is always in flux. The universe passes through endless cycles of creation and destruction. Each individual being has its own cycle of birth, growth and death. But ultimate reality remains unchanged ; even though it manifests itself again, and again and again.
