If we simply study our own bodies, we can understand how a living entity is always aloof from this bodily encagement. Every action of the body takes place by the interactions of the three modes of material nature. We can see at every moment many changes taking place in our bodies, but the spirit soul is aloof from all changes. One can neither create nor annihilate nor interfere with the actions of material nature. The living entity is therefore entrapped by the material body and conditioned in three stages, namely while awake, asleep and unconscious. The mind acts throughout all three conditions of life; the living entity in his sleeping or dreaming condition sees something as real, and when awake he sees the same thing as unreal. It is concluded, therefore, that under certain circumstances he accepts something as real and under other circumstances he accepts the very same thing as unreal. These matters are the subject of study for the empiric philosopher or the sāṅkhya-yogī. To come to the right conclusion, sāṅkhya-yogīs undergo severe austerities and penances, practicing control of the senses and renunciation.
All these different ways of determining the ultimate goal of life are compared to rivers, and Kṛṣṇa is compared to the ocean. As the rivers flow down toward the ocean, all attempts for knowledge flow toward Kṛṣṇa. After many, many births of endeavor, when one actually comes to Kṛṣṇa, he attains the perfectional stage. Kṛṣṇa says in the Bhagavad-gītā, kleśo ’dhikataras teṣām avyaktāsakta-cetasām: (BG 12.5) "All are pursuing the path of realizing Me, but those who have adopted courses without any bhakti find their endeavor very troublesome." Kṛṣṇa cannot be understood unless one comes to the point of bhakti.
Three paths are enunciated in the Bhagavad-gītā: karma-yoga, jñāna-yoga and bhakti-yoga. Those who are too much addicted to fruitive activities are advised to perform actions which will bring them to bhakti. Those who are addicted to the pursuit of empiric philosophy are also advised to act in such a way that they will realize bhakti. Karma-yoga is therefore different from ordinary karma, and jñāna-yoga is different from ordinary jñāna. Ultimately, as stated by the Lord in the Bhagavad-gītā, bhaktyā mām abhijānāti: (BG 18.55) only through execution of devotional service can one understand Kṛṣṇa. The perfectional stage of devotional service was achieved by the gopīs because they did not care to know anything but Kṛṣṇa. It is confirmed in the Vedas, kasminn u bhagavo vijñāte sarvam idaṁ vijñātaṁ bhavatīti. This means that simply by knowing Kṛṣṇa one automatically acquires all other knowledge.