Garuḍa Purāṇa 9
Garuḍa Purāṇa says that there are 8,400,000 types of species in existence broadly divided into four categories. They are aṇḍaja (born out of eggs like snakes, birds, fish, etc), svedaja (born of sweat like insects), udbhijja (born out of seeds – plant kingdom) and jarāyuja (viviparous). Out of these four categories, aṇḍaja is the lowest and jarāyuja is the highest. It is extremely difficult for the lower categories to attain a human form, which is considered as the highest. Among men, the one who deliberates on Vedic topics is the best. Gods, demigods, saints, sages and ancestors are always present in those places where virtues and dharma are upheld. Man is generally avaricious and longs for more and more. A man wants to become a demigod, a demigod wants to become a god and a god wants to become the Brahman. Their desires are endless. Men with avaricious desires fall into the hell and those without any desire comfortably reach the heaven. During childhood, one is attached to his parents; during adulthood, he is obsessed with his spouse and in his old age, he becomes obsessed with his grandchildren. Unfortunately, none is attached the Brahman, the Self. It is easier to get a person released from rope chains but a person who is bound by attachment to his spouse, children and grandchildren can never be freed.
Death is unavoidable. Man dies to be born again. He is born alone and dies alone. None accompanies him both in birth and death. He alone creates his karmas and he alone uses his karmas. If he has created good karmas, he enjoys his life and if he has accrued bad karmas, he suffers in life. His karmas transmigrate along with his soul. Once the physical body is burnt or buried, his association with the material world is over. The status of a man purely depends upon his previous deeds (karmas). One has to spend his wealth on virtuous deeds and actions. Any rite without complete faith does not yield results at all, either in this birth or in future births. A rite performed without faith does not accrue good karmas at all nor is he benefited in the present birth.
It is said that a man cannot attain heaven without begetting a son. Funeral rites performed by his son is more beneficial than the rites performed by other than his own son. Gifts given during his life time have more value and become more effective later. In the same way, sumptuous foods prepared and given by his own hands protect his soul (the subtle body) after his death. Any gifts (dāna) given at the time of one’s needs protects his soul. (Dāna should be given to those who really need it. If dāna is given to the one who already owns the article of dāna does not serve any purpose at all. If a dāna is given to the same person repeatedly, it is considered as a sin. The primary criteria of dāna is the choice of the person to whom the dāna is offered. If the receiver of dāna is rich and still receives dāna to accumulate more wealth for him, it causes the accrual of potent sin both to the receiver and the giver.) It is also said that one can perform rituals only when his body hale and healthy. If his body does not permit him to perform rituals, no sin accrues to him. If someone urges him to perform rituals in spite of his fragile health, he can safely ignore the advice.
If funeral rites are not performed properly, the departed soul roams about in the atmosphere for some time and will be born again as worms and insects. It is difficult to get a human form, but it is very easy for a man to be born as insects and animals due to his bad karmas. It must be remembered that liberation is possible only through the human form. Therefore, as long as his health permits, one should perform virtuous acts and provide gifts to the needy, to attain a human form again in order to get liberation.