SB 11.11.21

evaṁ jijñāsayāpohya
 nānātva-bhramam ātmani
upārameta virajaṁ
 mano mayy arpya sarva-ge
Word for word: 
evam — thus (as I have now concluded); jijñāsayā — by analytic study; apohya — giving up; nānātva — of material variety; bhramam — the mistake of rotating; ātmani — in the self; upārameta — one should cease from material life; virajam — pure; manaḥ — the mind; mayi — in Me; arpya — fixing; sarva-ge — who am all-pervading.
Translation: 
Coming to this conclusion of all knowledge, one should give up the false conception of material variety that one imposes upon the soul and thus cease one’s material existence. The mind should be fixed on Me, since I am all-pervading.
Purport: 

Although in previous verses Lord Kṛṣṇa has described the lifestyle and approach of the impersonal philosophers who meditate on the distinction between matter and spirit, the Lord here rejects the path of jñāna, or speculation, and comes to the final conclusion, bhakti-yoga. The path of jñāna is interesting only to one who does not know that Lord Kṛṣṇa is the Supreme Personality of Godhead, as stated in Bhagavad-gītā (7.19):

bahūnāṁ janmanām ante
 jñānavān mām prapadyate
vāsudevaḥ sarvam iti
 sa mahātmā su-durlabhaḥ

The words vāsudevaḥ sarvam iti, or “Vāsudeva is everything,” are similar to the words sarva-ge found in this verse. One should know why the Personality of Godhead is all-pervading. The first verse of Śrīmad-Bhāgavatam states, janmādy asya yataḥ: the Supreme Lord is the source of everything. And as stated in the previous verse of this chapter, He creates, maintains and annihilates everything. Thus the Lord is not all-pervading in the manner of air or sunlight; rather, the Lord is all-pervading as the absolute controller who holds in His hands the destiny of every living entity.

Everything is ultimately an expansion of Kṛṣṇa, and therefore there is really no other object of meditation besides Kṛṣṇa. Meditation upon any other object is also meditation on Kṛṣṇa but is imperfectly performed, as confirmed in Bhagavad-gītā by the word avidhi-pūrvakam. The Lord also states in the Gītā that all living entities are on the path back home, back to Godhead. Because of ignorance, however, some of them go backward or stop along the way, foolishly thinking that their journey is finished, when in fact they are suspended in one of the minor potencies of the Supreme Lord. If one wants to intimately understand the nature of the Absolute Truth, one must take to the path of love of Godhead. As stated in Bhagavad-gītā (18.55):

bhaktyā mām abhijānāti
 yāvān yaś cāsmi tattvataḥ
tato māṁ tattvato jñātvā
 viśate tad-anantaram

“One can understand the Supreme Personality as He is only by devotional service. And when one is in full consciousness of the Supreme Lord by such devotion, he can enter into the kingdom of God.”

The words nānātva-bhramam in this verse indicate false identification with the gross and subtle material bodies. The word bhramam indicates a mistake; it can also mean “wandering” or “rotating.” The conditioned living entity, because of his mistake of falling into illusion, is wandering through a succession of material bodies, sometimes appearing as a demigod and sometimes as a worm in stool. The word upārameta means that one should stop such fruitless wandering and fix one’s mind on the Absolute Truth, the Supreme Lord, who is the true object of everyone’s love. Such a conclusion is not sentimental but is the result of keen analytic intelligence (jijñāsayā). Thus after elaborately explaining to Uddhava many aspects of analytic knowledge, the Lord now comes to the ultimate conclusion, Kṛṣṇa consciousness, pure love of Godhead. Without such love there is no question of eternally fixing one’s mind on the Lord.

Quoting from the Viveka, Śrīla Madhvācārya states that nānātva-bhramam indicates the following illusions: considering the living entity to be the Supreme; considering all living entities to be ultimately one entity without separate individuality; considering that there are many Gods; thinking that Kṛṣṇa is not God; and considering that the material universe is the ultimate reality. All of these illusions are called bhrama, or mistakes, but such ignorance can be eliminated at once by the chanting of the holy names of Kṛṣṇa: Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare.