Prabhupada's lecture - Śrīmad-Bhāgavatam 1.8.18-19 - Bombay, April 9, 1971
Therefore śāstra says that alakṣya... Ārādhito yadi haris tapasā tataḥ kim: [Nārada-pañcarātra] "If one has come to the point of worshiping the Supreme Lord, there is no more necessity of undergoing severe austerities and penances." Because others, karmīs and yogis, for their sense gratification, karmīs, jñānīs, and yogis, they have to undergo severe austerities. But the bhakta, somehow or other, he can, if he simply learns how to love Kṛṣṇa, then he hasn't got to undergo severe austerities and penance. Immediately he is released. Because that is the perfectional stage. If you live in Kṛṣṇa, always loving... Just like the gopīs.
The gopīs, they learned how to love Kṛṣṇa. That's all. They never underwent any severe austerities like the great saintly persons going to Himalaya and pressing their nose and something like that. No, never did. Their only business was how to love Kṛṣṇa. Automatically. Without any... Of course, that stage is not easily obtained, but the śāstra says if you come to that stage, simply to love Kṛṣṇa, then you are on the highest platform of blissful life. Premāñjana-cchurita-bhakti-vilocanena santaḥ sadaiva hṛdayeṣu [Bs. 5.38]. Santaḥ, those who are devotees, they are twenty-four hours seeing God. That is to be... That is the highest stage of perfection. And by Kṛṣṇa consciousness movement, one can be brought to the platform, how to love Kṛṣṇa twenty-four hours without any cessation.