Accepting that there are two classes of philosophers, one believing in the existence of soul and the other not believing in the existence of the soul, there is no cause for lamentation in either case. Nonbelievers in the existence of the soul are called atheists by followers of Vedic wisdom. Yet even if, for argument’s sake, we accept the atheistic theory, there is still no cause for lamentation. Apart from the separate existence of the soul, the material elements remain unmanifested before creation. From this subtle state of unmanifestation comes manifestation, just as from ether, air is generated; from air, fire is generated; from fire, water is generated; and from water, earth becomes manifested. From the earth, many varieties of manifestations take place. Take, for example, a big skyscraper manifested from the earth. When it is dismantled, the manifestation becomes again unmanifested and remains as atoms in the ultimate stage. The law of conservation of energy remains, but in course of time things are manifested and unmanifested—that is the difference. Then what cause is there for lamentation either in the stage of manifestation or unmanifestation? Somehow or other, even in the unmanifested stage, things are not lost. Both at the beginning and at the end, all elements remain unmanifested, and only in the middle are they manifested, and this does not make any real material difference.
And if we accept the Vedic conclusion as stated in the Bhagavad-gītā (antavanta ime dehāḥ) that these material bodies are perishable in due course of time (nityasyoktāḥ śarīriṇaḥ) but that soul is eternal, then we must remember always that the body is like a dress; therefore why lament the changing of a dress? The material body has no factual existence in relation to the eternal soul. It is something like a dream. In a dream we may think of flying in the sky, or sitting on a chariot as a king, but when we wake up we can see that we are neither in the sky nor seated on the chariot. The Vedic wisdom encourages self-realization on the basis of the nonexistence of the material body. Therefore, in either case, whether one believes in the existence of the soul, or one does not believe in the existence of the soul, there is no cause for lamentation for loss of the body.
Ref >> Srila Prabhupada Vani.