Sāstra says that human life is not meant only for these four principles of life, bodily demands. There is another thing. That another thing is brahma-jijñāsā. Athāto brahma jijñāsā. A human being should be inquisitive to learn what is Absolute Truth. So that education is lacking. Therefore without this brahma-jijñāsā education, brahma jānātīti brāhmaṇaḥ . . . according to Vedic civilization, a brāhmin is learned. Paṇḍita. A brāhmin is called paṇḍita because brāhmin means one who knows Brahma. Brahma jānātīti brāhmaṇaḥ. Therefore he is called paṇḍita.
In India the brāhmin is addressed as paṇḍita. Paṇḍita means a brāhmin is expected to know Brahma; therefore he is brāhmin. Not by birth. Brahma jānāti. Janmanā jāyate śūdraḥ. By birth everyone is śūdra, fourth-class man. Janmanā jāyate śūdraḥ saṁskārād bhaved dvijaḥ. And when he's reformed by the purificatory process . . .
There are daśa-vidha-saṁskāra, ten kinds of purificatory process. When one undergoes all these processes and at last comes to the spiritual master, who gives him sacred thread as recognition of his second birth, dvija . . . dvija means second birth. One birth by the father and mother, and the other birth is by the spiritual master and Vedic knowledge. That is called second birth. Saṁskārād bhaved dvijaḥ. At that time he is given chance to study and understand what is Veda. Veda-pāṭhād bhaved vipraḥ. By studying very nicely all the Vedas, one becomes vipra. Then, when he actually realizes what is Brahma and his relationship with Him, then he becomes a brāhmin.
And above that situation, when from Brahma understanding, impersonal Brahma understanding, he comes to the platform of understanding Viṣṇu, Lord Viṣṇu, the Supreme Personality of Godhead, he becomes a Vaiṣṇava. This is the process. That is the perfectional process.
Kṛṣṇa therefore says in the Bhagavad-gītā, janma karma me divyaṁ yo jānāti tattvataḥ: "Anyone who knows Me in truth," what happens to him? Tyaktvā dehaṁ punar janma naiti (BG 4.9): "Such person, after giving up this body, do not come back again in this material world to accept a material body." Then what happens to him? Mām eti: "He comes to Me, back to home, back to Godhead."