Prabhupada's lecture - Śrīmad-Bhāgavatam 1.8.32 - Los Angeles, April 24, 1973
They are making scientific researches, but they do not know that every living entity is spirit soul. He has no birth. He has no death. He's eternal. Nityaḥ śāśvato 'yam, everlasting, purāṇaḥ, although oldest, na hanyate. The conclusion: na hanyate hanyamāne śarīre [Bg. 2.20]. So after the annihilation of this body the soul does not die. He accepts another body. This is our disease. This is called bhava-roga. Bhava-roga means material disease. So Kṛṣṇa, being the Supreme Living Entity, nityo nityānāṁ cetanaś cetanānām (Kaṭha Upaniṣad 2.2.13) Kṛṣṇa is exactly like us. Or we are imitation of Kṛṣṇa. The difference is Kṛṣṇa is vibhu, unlimited, and we are aṇu, we are limited. That is the difference. Otherwise, qualitatively, we are as good as Kṛṣṇa.
Therefore whatever propensities Kṛṣṇa has, we have got all these propensities. Kṛṣṇa has the propensity to love the other sex. Therefore we have got this propensity, to love the other sex. The beginning of love is there in Rādhā and Kṛṣṇa, eternal love between Rādhā and Kṛṣṇa. So we are also seeking eternal love, but because we are conditioned by the material laws, it is interrupted. It is interrupted.