Kṛṣṇa also says in the Bhagavad-gītā that yoginām api sarveṣāṁ mad-gatenāntarātmanā: "One who is always thinking of Me within himself, he is first-class yogi." Yoginām api sarveṣāṁ (BG 6.47). There is no need of speculating. Simply this easy process, thinking of Kṛṣṇa. Kṛṣṇa says in the Bhagavad-gītā that yoginām api sarveṣāṁ. All big, big yogis, there may be, but a person who is always absorbed in thought of Kṛṣṇa within himself, he is greater than all such big, big yogis. Greater than the greatest yogi. Yoginām api sarveṣāṁ mad-gatenāntarātmanā. Mad-gata means his life is so molded that he cannot stay without thinking of Kṛṣṇa. Mad-gata. He has become absorbed. That is samādhi. Mad-gatenāntarātmanā śraddhāvān. Not for artificial makeshow, but śraddhāvān, with faith and love. Śraddhāvān bhajate yo māṁ sa me yuktatamo mataḥ.
But how this stage can be attained? This stage can be attained only by persons who have developed pure love of God. Just like... It is very easy to understand. If you love somebody, always you'll think of him. In this material world also, the so-called love... If a boy loves some girl or a girl loves some boy, naturally, he thinks always of him. So to think of Kṛṣṇa always means you must develop your love. That is there within yourself, everyone. Kṛṣṇa-bhakti nitya-siddha. It is eternally truth, eternally fact, that you have got your love for Kṛṣṇa within yourself. Simply you have to revive. That process is easy, very easy. The chanting. Ceto-darpaṇa-mārjanam (CC Antya 20.12). The glittering thing, Kṛṣṇa, or the Kṛṣṇa light. Kṛṣṇa light is within everyone. Nitya-siddha: eternally truth. But it is covered by material contamination. And by chanting Hare Kṛṣṇa mantra these nasty, dirty things will be cleansed. Ceto-darpaṇa-mārjanam. This is polishing. Polishing. Just like mirror, you polish; you can see very nicely the reflection of your nice face. Similarly, if you polish your heart by chanting, ceto-darpaṇa-mārjanam, then immediately you develop your dormant love of Kṛṣṇa. And as soon as the dormant love of Kṛṣṇa is awakened, immediately you are liberated. Bhava-mahā-dāvāgni-nirvāpaṇam.