Srila Prabhupada explains who can understand?
Yogesvara: "Is there some, any qualities, in the sense that some people have more receptivity towards the divine than other people?"
Prabhupada: Yes. That I explained, sattva-guna, rajo-guna, tamo-guna. Those who are in sattva-guna, they can understand easily. Those who are in rajo-guna, they have got difficulty. And those who are in tamo-guna, they cannot. 740615rc.par Conversations
Srila Prabhupada explains how to hear properly?
One has to learn Bhāgavatam from the representative of Śukadeva Gosvāmī, and no one else, if one at all wants to see Lord Śrī Kṛṣṇa in the pages. That is the process, and there is no alternative. Sūta Gosvāmī is a bona fide representative of Śukadeva Gosvāmī because he wants to present the message which he received from the great learned brāhmaṇa. Śukadeva Gosvāmī presented Bhāgavatam as he heard it from his great father, and so also Sūta Gosvāmī is presenting Bhāgavatam as he had heard it from Śukadeva Gosvāmī. Simple hearing is not all; one must realize the text with proper attention. The word niviṣṭa means that Sūta Gosvāmī drank the juice of Bhāgavatam through his ears. That is the real process of receiving Bhāgavatam. One should hear with rapt attention from the real person, and then he can at once realize the presence of Lord Kṛṣṇa in every page. The secret of knowing Bhāgavatam is mentioned here. No one can give rapt attention who is not pure in mind. No one can be pure in mind who is not pure in action. No one can be pure in action who is not pure in eating, sleeping, fearing and mating. But somehow or other if someone hears with rapt attention from the right person, at the very beginning one can assuredly see Lord Śrī Kṛṣṇa in person in the pages of Bhāgavatam. Srimad-Bhagavatam : Canto 1:"Creation" : SB 1.3: Krsna Is the Source of All Incarnations : SB 1.3.44 : PURPORT
"... That is brahma-bhūtaḥ state. So this can be awakened by hearing. Therefore the Vedic mantra is called śruti. One has to receive this awakening through the ear. Śravaṇaṁ kīrtanaṁ viṣṇoḥ [SB 7.5.23]. Always one has to hear and chant about Viṣṇu. Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. Then ceto-darpaṇa-mārjanam [Cc. Antya 20.12], everything will be cleansed, and he'll come to understand that "I am eternal servant of Kṛṣṇa."
Srila Prabhupāda: When you become Vaiṣṇava, the brahminism is already included. General process is, unless one does not come to the sattva-guṇa platform, he cannot understand what is Kṛṣṇa consciousness. That is the general rule. But this Kṛṣṇa, devotional service, Kṛṣṇa consciousness movement, is so nice that simply by hearing about Kṛṣṇa, you come to immediately to the brahminical platform. Naṣṭa-prāyeṣu abhadreṣu nityaṁ bhāgavata-sevayā [SB 1.2.18]...." Bhagavad-gita Lectures : Bg 2: Lectures : Bhagavad-gita 2.20 -- Hyderabad, November 25, 1972
"... Śrīla Jīva Gosvāmī says that unless we accept this principle that Kṛṣṇa or God has got inconceivable power, acintya-śakti, we cannot understand. If we put Kṛṣṇa within the jurisdiction of my limited understanding, that is not understanding of Kṛṣṇa..." Bhagavad-gita Lectures : Bg 2: Lectures : Bhagavad-gita 2.23-24 -- London, August 27, 1973
So less intelligent class of men, they cannot understand Kṛṣṇa. Therefore śāstra says, ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ [Cc. Madhya 17.136]. These indriya, these material senses, cannot speculate to understand the Supreme Personality of Godhead. That is not possible Lectures : Bhagavad-gita Lectures :
So our process is to receive the perfect knowledge from the perfect source and distribute it. We don't manufacture knowledge. Therefore we are presenting Bhagavad-gītā as it is, as it is. The Bhagavad-gītā is already perfect. Why shall I interpret with my imperfect senses? This is cheating. But people want to be cheated. Vaṣcita-vaṣcaka-sampradāya. The whole world is full of cheaters and cheated. Because we want to be cheated, there are so many cheaters. They don't want real thing. Here is the real thing, Bhagavad-gītā, the Supreme Personality of Godhead speaking personally about Himself. Why should we interpret? Does it mean that the Supreme Personality of Godhead, the supreme authority, left something unexplained to be interpreted later on by some rascals? No. But the rascals dare; they interpret. That is cheating. That is another faultBg 1: Lectures : Bhagavad-gita 1.13-14 -- London, July 14, 1973
So ordinary man cannot understand. Therefore they interpret foolishly, speculate, and demonstrate their rascaldom. That's all. Even big, big scholars. So they cannot understand because they are not devotee. It is meant for the devotee Lectures : Bhagavad-gita Lectures : Bg 1: Lectures : Bhagavad-gita 1.20 -- London, July 17, 1973
There is no difficulty. Simply one must be sincere, not sinful. But a sinful man cannot understand Him. Bhagavad-gita Lectures : Bg 1: Lectures : Bhagavad-gita 1.20 -- London, July 17, 1973
Bhaktyā mām abhijānāti yāvān yaś cāsmi tattvataḥ [Bg. 18.55]. Only by devotion, simply. He could have said, "By high, topmost knowledge" or "By yogic process" or "By acting, becoming a very great karmī, worker, one can understand Me." No, he has never said, never said. So the karmīs, jṣānīs, yogis, they are all rascals. They cannot understand Kṛṣṇa. All rascals. Karmīs are third-class rascals, the jṣānīs are second-class rascal, and the yogis are first-class rascal. That's all. Lectures : Bhagavad-gita Lectures : Bg 1: Lectures : Bhagavad-gita 1.20 -- London, July 17, 1973
It is not so easy thing that "I do everything, whatever I like." Some rascals preach that "Oh, religion has nothing to do with your eating. You can eat anything you like, and still you become a religious man." This is all nonsense. Nobody can become religious man if he is attracted by sinful activities. It is not possible. You must stop sinful activities. That is first condition. Otherwise you cannot understand what there... People... Perhaps, in this Kṛṣṇa conscious, except this Kṛṣṇa conscious movement, all rascals, they do not know what is God. Lectures : Bhagavad-gita Lectures : Bg 1: Lectures : Bhagavad-gita 1.21-22 -- London, July 18, 1973
This knowledge has to be received by paramparā system. Evam paramparā-prāptam imaṁ rājarṣayo viduḥ [Bg. 4.2]. So simply by academic career, by knowledge of ABCD, you cannot understand Bhagavad-gītā. In the Bhagavad-gītā it is said, bhakto 'si priyo 'si me [Bg. 4.3], without becoming bhakta... Therefore Sanātana Gosvāmī has forbidden that "Don't hear anything about Kṛṣṇa from a person who is not a Vaiṣṇava." Avaiṣṇava-mukhodgīrṇa-pūta-hari-kathāmṛtaṁ śravanaṁ na karta... This is prohibited. You cannot hear. But this audience or the students, they also do not know that "Here is a rascal, he is not a devotee, he is not a Vaiṣṇava. Why shall we hear from him Bhagavad-gītā?" The first condition is bhakto 'si. And the prohibition is also by ācāryas. Avaiṣṇava-mukhodgīrṇa-pūta-hari-kathāmṛtaṁ śravanaṁ na kartavyam. Pūta-hari-kathāmṛtam. Hari-kathā, talks of Kṛṣṇa, they are by themselves pure. But still, it is prohibited that if it is spoken by an avaiṣṇava, nondevotee, one should not hear, should not hear. Must immediately reject. First of all, we have to see who is going to speak about Kṛṣṇa. Is it a devotee of Kṛṣṇa? Is he a Vaiṣṇava or not? If he is not, then immediately reject: "Oh, we are not going to hear from you." But people do not know. Any rascal speaking about Bhagavad-gītā we hear. That is not the process. Then you will misunderstand. Avaiṣṇava-mukhod..., sarpocchiṣṭaṁ payo yathā. Just like milk is very good food, everyone knows. But when it is touched by the tongue of the serpent, it is poison immediately. So we cannot drink poison. Don't hear Bhagavad-gītā or any talk about Kṛṣṇa from a person who is not a Vaiṣṇava, who is not a devotee of Kṛṣṇa. We'll misunderstand. Just like they will say, they will say, "Oh, Kṛṣṇa is engaging Arjuna for fighting, for committing so many sinful activities." No, that is not the fact. Kṛṣṇa is engaging Arjuna fighting, to fighting, just to serve His purpose. Paritrāṇāya sādhūnāṁ vināśāya ca duṣkṛtam [Bg. 4.8]. Lectures : Bhagavad-gita Lectures : Bg 1: Lectures : Bhagavad-gita 1.44 -- London, July 31, 1973