(Srila Prabhupada in Moscow, 1971)
Prabhupāda: The modern civilization is based on rajas-tamo-bhāvāḥ. Nobody is satisfied. Everyone is greedy. And lusty. Kāma-lobhādayaś ca ye. Kāma. So long you are lusty, so long you are greedy, there is no question of devotional service. There is no question of advancement to spiritual life. So therefore you have to come to the platform of sattva-guṇa, where simply knowledge... There is no other thing, ignorance or greediness, only knowledge.
So at that time, it is said, ceta etair anāviddham. Because everything is within the heart. We become greedy, we become lusty on account of distortion of the heart disease, kāma. Tadā hṛdi lobha-kāmau apahinoti. That is a heart disease. This kāma and lobha is a heart disease. Actually, you don't require this, but it is a kind of disease. "More and more and more and more and more." Never satisfied. So we have to cure this disease. And this process, simple process, Caitanya Mahāprabhu has given: ceto-darpaṇa-mārjanam... To cure the heart disease of lusty desires and greediness is chanting Hare Kṛṣṇa mahā-mantra. Paraṁ vijayate śrī-kṛṣṇa-saṅkīrtanam. These are the shastric injunction, and spoken by personalities like Lord Caitanya and other ācāryas.
So we have to follow. Mahājano yena gataḥ sa panthāḥ (CC Madhya 17.186). Don't follow rascals and fools. Then it will be useless waste of time. Follow the great ācāryas. Ācāryavān puruṣo veda. One who is ācāryavān, who has accepted ācārya, he knows. Others, all are fools, rascals. Ācāryavān. Ācāryopāsanam. In the Bhagavad-gītā it is said, amānitvam adambhitvam ahiṁsā kṣāntir ārjavam, ācāryopāsanam (BG 13.8). You have to first of all worship the ācārya. Tad-vijñānārthaṁ sa gurum evābhigacchet (MU 1.2.12). Guru and ācārya, the same thing. So these are the process. Mahājano yena gataḥ.
You cannot manufacture your ways of thinking. What you are? You are most insignificant living entity. And without following the ācāryas, without following the mahājanas, without following the śāstra, how you can teach? But people are doing that. Without being followed by the ācārya, without being followed by the śāstras, they become guru, they become svāmī, they become yogī. It is useless.
(Srila Prabhupada Lecture, Calcutta, September 27, 1974)