(Prabhupada's lecture - Śrīmad-Bhāgavatam 1.16.3 - Los Angeles, December 31, 1973)
So that has to be practiced. Sadā tad-bhāva-bhāvitaḥ [Bg. 8.6]. If you always chant Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare, that means you remember Kṛṣṇa always. So there is chance, ninety-nine percent chance, that at the time of your death you will think of Kṛṣṇa and your life is successful. Very simple method. Make always your mind absorbed in Kṛṣṇa. Naturally at the time of death you will think of Kṛṣṇa. Mad-yājino 'pi yānti mām [Bg. 9.25]. That is confirmed in the Bhagavad-gītā. Tyaktvā dehaṁ punar janma naiti mām iti kaunteya [Bg. 4.9]. Such person, Kṛṣṇa conscious person, who knows Kṛṣṇa... If you think of Kṛṣṇa, naturally you know of Kṛṣṇa. You know of Kṛṣṇa. Kṛṣṇa is within your heart.
So if you think of Kṛṣṇa, then gradually you become Kṛṣṇized. Just like you put the iron rod in the fire. Gradually it becomes fire. Warm, warmer, warmer, then red-hot. When it is red-hot it is fire. Whenever you touch, it will burn immediately. Similarly, if you think of Kṛṣṇa, the same example... Touching fire. So Kṛṣṇa will purify you. Śṛṇvatāṁ sva-kathāḥ kṛṣṇaḥ puṇya-śravaṇa-kīrtanaḥ [SB 1.2.17]. Just like you are being purified by hearing about Kṛṣṇa daily. Otherwise why you are coming here? We have no money to bribe you to come here. You are feeling, becoming Kṛṣṇized; therefore you are coming.