This is the system of varṇāśrama-dharma—four kinds of varṇas and four kinds of āśrama. It is very scientific. The whole idea of human civilization should be how to push one to Kṛṣṇa consciousness, to Viṣṇu. Because they do not know, na te viduḥ svārtha-gatiṁ hi viṣṇum (SB 7.5.31). The real interest is to approach Viṣṇu, to go back to home, go back to Godhead. That he does not know. He is entangled with these material affairs. Anartha. They are called anartha. They are not required.
When you get a human form of body you must know that your food and shelter is already ordained. You don't require to try for this. Even the birds and beasts, they do not try for their food and shelter. They are certain that, "Somewhere we have got our shelter and there is somewhere my food."
Eko bahūnāṁ yo vidadhāti kāmān (Kaṭha Upaniṣad 2.2.13). Kṛṣṇa, the supreme patron, He is supplying food to everyone. He is supplying food to the elephant, who eats one time one hundred pounds, and He is supplying a grain of sugar to the ant also. So why should I bother about my fooding? That is śaraṇāgati. When a man becomes śaraṇāgata, he knows perfectly well that, "Somewhere or other there is my food."