So as soon as that individual soul is seriously engaged in hearing about Kṛṣṇa, immediately the dirty things within his heart becomes cleansed. Ceto-darpana-mārjanaṁ bhava-mahā-dāvāgni-nirvāpanam (CC Antya 20.12). And as soon as the heart is cleansed, his all problems of this material world is solved. Bhava-mahā-dāvāgni-nirvāpanam. Because he understands. Cleansing the heart means to understand that he is not Kṛṣṇa. He's part and parcel of Kṛṣṇa. His duty is to serve Kṛṣṇa. This is cleansing of heart. So long it is not cleansed...
Just like the Māyāvādī philosophers, they are thinking themselves that they are Kṛṣṇa. "I am God." That is unclean. Vimukta-māninaḥ. Tvayy asta-bhāvād aviśuddha-buddhayaḥ (SB 10.2.32). Because their intelligence is not yet clear, it is still with dirty things, therefore they are thinking that they are Kṛṣṇa. No. Kṛṣṇa is the Supreme Personality of Godhead, and we are eternal servant of Kṛṣṇa. This is the philosophy.