Why a Person Reincarnates?
The reason a person reincarnates is really quite simple: because of material desire.
There was once a spiritual master who wanted to teach his disciple about material desires. The teacher told his disciple: “ I know of an old man near here who is on his deathbed; bring your beautiful young sister and let us go and visit him. Before they entered the room where the old man was dying, the spiritual master instructed his disciple: “When you go into the room, watch the old man’s eyes. When they entered the room the disciple immediately noticed that the old man could not keep his eyes off the beautiful young girl. Although the old man was bedridden and could not move, still the desire for sexual pleasure was there. Even his body is no longer capable for such activity but his desire for sexual enjoyment was as strong as ever.
So in this way the spiritual master taught his disciple that the desire for sensual enjoyment continues even after the sense organ themselves can no longer function. In other words, the desire for sensual enjoyment outlives the particular sense organs that are being used to achieve such enjoyment.
The death of the body does not mean the death of the material desires. When the self leaves the gross physical bodies, she takes with her whatever desires she still has.
The story of the old man who still desired sexual pleasure even though his organs could no longer function helps us to better understand the relationship between the subtle body (material desires and plans) and the gross body. The subtle body is the reservoir of desires for sensual pleasure; the groos body is the vehicle or tool with which the self attempts to fulfil such desire.
The tongue is an external, gross manifestation of the desire to taste; the nose is the gross manifestation of the desire to enjoy aromas; and so on.
When a person “loses” the use of one of his sense organs- his eyes or his ears, for example – he feels a great loss. Why? Because the organ was a means of achieving a particular type of sense pleasure. The sense organs are the link between the sensual desires seated in the subtle body and the objects of sense pleasure. A man’s reproductive organ are the link between his desire for sexual pleasure and the body of a beautiful woman. Without the sexual organ, without a link, a person couldn’t actively try to fulfil his desires. Just like the old man – he had sexual desire, but he didn’t have a properly functioning sex organ. At death, we leave behind the “link”, the vehicle of sense gratification. But we do not leave behind our desire for sensual enjoyment, our desire to lord over material nature. We are still covered by the desire to be in the world of matter. And God knows this. God knows the mind and the heart of the every individual self.
Such a person must factually know the greatest of all, who is unembodied, omniscient, beyond reproach, without veins, pure and uncontaminated, the self sufficient philosopher who has been fulfilling everyones desire since time immemorial.
Sri Ishopanishad, Mantra 8
Man proposes, God disposes. Material nature, under God’s arrangement, provides us with successive gross material bodies because this is in fact what we want. And as long as we want to be the lord and enjoyer of matter, God will provide us with gross material bodies, one after another.
The living entity by nature has minute independence to choose her own good or bad fortune, but when she forgets her Supreme Master, The personality of Godhead, she gives herself up unto the modes of material nature; she identifies herself with the body, and for the interest of the body becomes attached to various activities. Sometimes she is under the influence of the mode of ignorance, sometimes the mode of passion. Sometimes the mode of goodness. The living entity thus gets different types of bodies under the modes of material nature.
Srimad Bhagavatam 4:29:26-27