The men and other living entities within this cosmic manifestation are controlled by the three modes of nature. For the living entities controlled by the base qualities of nature, passion and ignorance, there is no possibility of understanding God. Even those in the mode of goodness, like the many demigods and great ṛṣis described in these verses, cannot understand the activities of the Supreme Personality of Godhead. As stated in Bhagavad-gītā, one who is situated in the devotional service of the Lord is transcendental to all the material qualities. Therefore the Lord personally says that no one can understand Him but the bhaktas, who are transcendental to all material qualities ( bhaktyā mām abhijānāti ). As stated by Bhīṣmadeva to Mahārāja Yudhiṣṭhira in Śrīmad-Bhāgavatam (1.9.16) :

na hy asya karhicid rājan pumān veda vidhitsitam yad-vijijñāsayā yuktā muhyanti kavayo ’pi hi

“O King, no one can know the plan of the Lord [Śrī Kṛṣṇa]. Even though great philosophers inquire exhaustively, they are bewildered.” No one, therefore, can understand God by speculative knowledge. Indeed, by speculation one will be bewildered ( muhyanti ). This is also confirmed by the Lord Himself in Bhagavad-gītā (7.3) :

manuṣyāṇāṁ sahasreṣu kaścid yatati siddhaye yatatām api siddhānāṁ kaścin māṁ vetti tattvataḥ

Among many thousands of men, one may endeavor for perfection, and even among the siddhas, those who have already become perfect, only one who adopts the process of bhakti, devotional service, can understand Kṛṣṇa.