Perfect knowledge of oneself as Krishna's eternal servant immediately liberates one from all sinful reactions and material bondage.Listen — Srila Prabhupada Uvaca
The Nectar of Devotion — November 5, 1972, Vṛndāvana 721105ND-VRNDAVAN [35:10 Minutes] NOD_721105ND-VRNDAVAN Pradyumna: [reading:] "...committed criminal acts but is not yet arrested for them. Now, as soon as he is detected, arrest is awaiting for him..., is awaiting him. Similarly, for some of our sinful activities we are awaiting distresses in the future, and for others, which are mature, we are suffering at the present moment. In this way..." Prabhupāda: Yes.
This is the chain of accepting different types of bodies, one after another, according to the sinful activity. On the total, without being sinful, nobody accepts this material body. Because in the Bhagavad-gītā we understand, yeṣām anta-gataṁ pāpam: "One who has finished the reaction of his sinful activities," te dvandva-moha-nirmukta... [Bg. 7.28].
Yeṣāṁ anta-gataṁ pāpaṁ janānāṁ puṇya-karmaṇām... Puṇya-karma. Puṇya-karma means..., the sublime puṇya-karma is devotional service. Śravaṇaṁ kīrtanaṁ viṣṇoḥ smaraṇaṁ pāda-sevanam [SB 7.5.23]. This is the topmost puṇya-karma. Because, as it is stated in the Bhāgavata, śṛṇvatāṁ sva-kathāḥ kṛṣṇaḥ puṇya-śravaṇa-kīrtanaḥ [SB 1.2.17].
Simply if we hear about Kṛṣṇa, that is puṇya. Even you do not understand, do not take it very seriously, if we simply give aural reception to the words of Kṛṣṇa, that activity itself is puṇya. Puṇya-śravaṇa kīrtanaḥ. So one who has got, I mean, advanced in hearing about Kṛṣṇa, that is the result of multiforms of multivarieties of pious activities. Vāsudeva-kathā-ruciḥ [SB 1.2.16].
Vāsudeva-kathā-ruciḥ is the resultant action... Kṛta-puṇya-puñjāḥ [SB 10.12.11]. These words are used. Just like when the cowherds boys were playing with Kṛṣṇa, Śukadeva Gosvāmī said that "These boys are kṛta-puṇya-puñjāḥ.
Heaps of pious activities they have performed; therefore they have got this chance of playing personally with the Supreme Personality of Godhead." So, so long we are tinged with sinful activities, we have to accept different varieties of body, either the body of Lord Brahmā or the body of an ant, indragopa, a small microbic insect, yas tv indragopam athavendram aho sva-karma [Bs. 5.54]. From this indragopa, the microscopic insect which is called indragopa insect, from this indragopa insect to the real Indra, the king of heaven, everyone is suffering or enjoying—actually it is suffering—the resultant action of his karma. It doesn't matter what kind of body a living entity has got, but the body itself is the symptom, is the sign that one is sinful. This is the conclusion of the śāstra.
Because as soon as one is free from sinful activities, at that time he goes back to home, back to Godhead. Tyaktvā dehaṁ punar janma naiti mām eti [Bg. 4.9]. So our this material body is achieved due to sinful activities. And sinful activities are performed due to ignorance. Therefore knowledge is essential.