SB 6.3.14-15

ahaṁ mahendro nirṛtiḥ pracetāḥ
 somo ’gnir īśaḥ pavano viriñciḥ
āditya-viśve vasavo ’tha sādhyā
 marud-gaṇā rudra-gaṇāḥ sasiddhāḥ
anye ca ye viśva-sṛjo ’mareśā
 bhṛgv-ādayo ’spṛṣṭa-rajas-tamaskāḥ
yasyehitaṁ na viduḥ spṛṣṭa-māyāḥ
 sattva-pradhānā api kiṁ tato ’nye
Synonyms: 
aham — I, Yamarāja; mahendraḥ — Indra, the King of heaven; nirṛtiḥ — Nirṛti; pracetāḥ — Varuṇa, the controller of water; somaḥ — the moon; agniḥ — fire; īśaḥ — Lord Śiva; pavanaḥ — the demigod of the air; viriñciḥ — Lord Brahmā; āditya — the sun; viśve — Viśvāsu; vasavaḥ — the eight Vasus; atha — also; sādhyāḥ — the demigods; marut-gaṇāḥ — masters of the wind; rudra-gaṇāḥ — the expansions of Lord Śiva; sa-siddhāḥ — with the inhabitants of Siddhaloka; anye — others; ca — and; ye — who; viśva-sṛjaḥ — Marīci and the other creators of the universal affairs; amara-īśāḥ — the demigods like Bṛhaspati; bhṛgu-ādayaḥ — the great sages headed by Bhṛgu; aspṛṣṭa — who have not been contaminated; rajaḥ-tamaskāḥ — by the lower modes of material nature (rajo-guṇa and tamo-guṇa); yasya — of whom; īhitam — the activity; na viduḥ — do not know; spṛṣṭa-māyāḥ — who are illusioned by the illusory energy; sattva-pradhānāḥ — chiefly in the mode of goodness; api — although; kim — what to speak of; tataḥ — than them; anye — others.
Translation: 
I, Yamarāja; Indra, the King of heaven; Nirṛti; Varuṇa; Candra, the moon-god; Agni; Lord Śiva; Pavana; Lord Brahmā; Sūrya, the sun-god; Viśvāsu; the eight Vasus; the Sādhyas; the Maruts; the Rudras; the Siddhas; and Marīci and the other great ṛṣis engaged in maintaining the departmental affairs of the universe, as well as the best of the demigods headed by Bṛhaspati, and the great sages headed by Bhṛgu are all certainly freed from the influence of the two base material modes of nature, namely passion and ignorance. Nevertheless, although we are in the mode of goodness, we cannot understand the activities of the Supreme Personality of Godhead. What, then, is to be said of others, who, under illusion, merely speculate to know God?
Purport: 

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.