After being liberated from all these designation, one begins his devotional service, devotional life. And Kṛṣṇa says: "If one wants to know Me, then he must accept." Bhaktyā mām abhijānāti yāvān yaś cāsmi tattvataḥ (BG 18.55). Tattvataḥ. If one wants to know Kṛṣṇa, God, as He is, then he has to accept the process of devotional service. Bhaktyā mām abhijānāti.
Evaṁ prasanna-manaso bhakti-yogena (SB 1.2.20). There is another verse in the Śrīmad-Bhāgavatam: evaṁ prasanna-manaso bhagavad-bhakti-yogataḥ. By practicing the bhagavad-bhakti-yoga, bhagavad-bhakti-yoga prasanna manaso, one has to become first of all joyful by identifying himself with the spirit. Brahmā bhūtaḥ prasannātmā na śocati na kāṅkṣati (BG 18.54).
Then, when he becomes joyful, he understands that, "I am not this material body; I am spirit soul. I am not American, I am not Indian, I'm not brāhmin, I am not this, this, this, so many things . . . no, I am spirit soul. I am part and parcel of Kṛṣṇa." This is called brahma-bhūtaḥ.
Evaṁ prasanna-manaso. When one becomes brahma-bhūtaḥ, self-realized, at that time, he becomes prasanna-manaso, joyful. Na śocati na kāṅkṣati: he has no more lamentation or hankering. Evaṁ prasanna. In this state of life, prasanna-manaso, evaṁ prasanna-manaso bhagavad-bhakti-yogataḥ (SB 1.2.20), by practicing bhagavad-bhakti yoga, bhagavat-tattva-vijñānaṁ mukta-saṅgasya jāyate.
At that time, one can understand what is the science of God, bhagavat-tattva. It is not a sentiment, it is a vijñāna, science. Bhagavad-tattva-vijñāna. So who can understand this bhagavad-tattva-vijñāna, science? Mukta-saṅga. One who is liberated from this material contamination, he can understand.