Kṛṣṇa said in the beginning, that cātur-varṇyaṁ mayā sṛṣṭaṁ guṇa-karma-vibhāgaśaḥ (BG 4.13). The four classes of men, according to quality, they should be engaged in different types of occupation, guṇa-karma. First of all, guṇa. Guṇa means quality. In the material world also, practically we see, if we want to work in a certain type of occupation, first of all it is examined whether I have got the quality. Suppose if I want to work as an engineer, so I must possess the quality first of all, whether I can act as an engineer. Similarly, if I want to work as a lawyer, then I must have the quality, qualification. Similarly, different type of quality, different type of qualification, and then different type of work. Guṇa-karma-vibhāgaśaḥ.
So that requires guidance. And who is the guide? The father is the guide, the king, the government is the guide, the elderly guru is the guide. There must be guide. Gurur na sa syāt pitā na sa syāj jananī na sā syāt (SB 5.5.18). In this way . . . sva-jano na sa syāt na mocayed yaḥ samupeta-mṛtyum. These laws are unknown at the present moment in this age. There are so many gurus, so many fathers, so many relatives, so many husbands. There are so many guides, but they do not know what is the aim of life. Therefore śāstra says that, "If you do not know what is the aim of life, you should not become a guru, you should not become a father, you should not become a mother." Jananī na sā syāt.
So what is the aim of life? The aim of life . . . na mocayed yaḥ samupeta-mṛtyum. Samupeta-mṛtyum. We have got this disease, mṛtyu: we have to die. We are making so many plans for our happiness, but where is the plan for stopping your death? That is the ultimate goal of life, but they do not know it. Na mocayed yaḥ samupeta-mṛtyum. Kṛṣṇa says . . . everything is explained in the Bhagavad-gītā. Therefore we are repeatedly asking everyone to study Bhagavad-gītā as it is. Don't become a learned scholar and interpret foolishly or differently from Bhagavad-gītā. That is not meaning. As it is, as Kṛṣṇa says, try to understand Bhagavad-gītā. Everything is there.
So Kṛṣṇa says that our real problem of life is janma-mṛtyu-jarā-vyādhi-duḥkha-doṣānudarśanam (BG 13.9). That is the problem, repetition of birth, bhūtvā bhūtvā pralīyate (BG 8.19). We take one body according to karma, karmaṇā daiva-netreṇa jantur dehopapattaye (SB 3.31.1). We get a body according to karma, daiva-netreṇa. That is not in your hand. Suppose if you are living like cats and dogs, the nature's way is that you get next life the dog's body, cat's body or hog's body. And if you are working just like a god, godly, with good qualification, godly qualification, then you become next life demigod. You get your situation in the higher planetary system. These are all explained in the Bhagavad-gītā. How do you know? Ūrdhvaṁ gacchanti sattva-sthāḥ (BG 14.18). If you act just like a qualified brāhmaṇa, sattva-sthā—sattva-sthā means brāhmaṇa—then you get your promotion in the higher planetary system, ūrdhvam. Ūrdhvaṁ gacchanti sattva-sthāḥ. If you act like a brāhmaṇa, then get your promotion to the higher planetary system, Janaloka, Maharloka, Tapoloka, Brahmaloka, Siddhaloka. There are so many planets. The people do not know. There is no such education. But we have got this knowledge from the Vedic literature. Ūrdhvaṁ gacchanti sattva-sthā madhye tiṣṭhanti rājasāḥ. If you have got the qualification of rajo-guṇa, creative energy, then you remain in the middle planetary system, Bhūr, Bhuvar, Svar. Those who are brāhmaṇas, know gāyatrī-mantra, oṁ bhūr bhuvaḥ svaḥ. And jaghanya-guṇa-vṛtti-sthā adho gacchanti tāmasāḥ. Tāmasāḥ, tamo-guṇa, jaghanya, abominable, nasty, unclean, eating nasty things.Then jaghanya-guṇa-vṛtti-sthā adho gacchanti tāmasāḥ, they go to the lower planetary system, Tala, Atala, Vitala, Pātāla, Rasātala, Talātala—there are so many planets—or in the animal kingdom.