If you take to these principles, then you make advance in spiritual consciousness, in Kṛṣṇa consciousness, and as you make advancement in Kṛṣṇa consciousness, then you become perfect in knowledge. Otherwise, what is the use of becoming scientist or philosopher who cannot say what is next life?
But these students, they can very easily say what is next life, what is God, what I am, what is our relationship. This knowledge you'll find perfectly, because they are reading perfect book of knowledge, Bhagavad-gītā, Śrīmad-Bhāgavatam. So this is our process, very easy. Anyone can adopt and make his life perfect. And if somebody says that "I am not educated. I cannot read book," still, there is possibility, you simply chant Hare Kṛṣṇa.
So you have got tongue. You have got ear. Kṛṣṇa has given you. And you'll be surprised to know that Kṛṣṇa is realized through tongue, not through eyes, not through ears. Tongue. Of course, after tongue, the other senses are following. Tongue is the chief. So we have to control the tongue. How to control? Chant Hare Kṛṣṇa and taste kṛṣṇa-prasādam. That's all.
Sevonmukhe hi jihvādau svayam eva sphuraty adhaḥ. Ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ (CC Madhya 17.136). You cannot understand Kṛṣṇa by exercising your sensual perception, speculation. It is not possible. Kṛṣṇa is so great that He is not within your sensual exercise. No. He can be understood by surrender. Kṛṣṇa therefore recommends this process, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66). Because our disease is rebellious, no authority.
We don't want any authority. That is our disease. We say we don't want any authority, but nature is so strong that he forces his authority upon you. You are forced to accept the authority of nature by your sensual exercise. You cannot say that, "I am independent." You may say all nonsense that, "I don't want authority," but you are . . . everyone is under authority. And that is our foolishness. We are under authority; still, we say we don't want any authority. This is called māyā, illusion.
So the best authority is Kṛṣṇa. If we . . . after all, we have to accept authority. So why not best authority, Kṛṣṇa? Then your life becomes successful.