As stated in Bhagavad-gītā (2.71):

vihāya kāmān yaḥ sarvān
 pumāṁś carati niḥspṛhaḥ
nirmamo nirahaṅkāraḥ
 sa śāntim adhigacchati

“A person who has given up all desires for sense gratification, who lives free from desires, who has given up all sense of proprietorship and who is devoid of false ego — he alone can attain real peace.” Śrīla Prabhupāda comments, “To become desireless means not to desire anything for sense gratification. In other words, desire for becoming Kṛṣṇa conscious is actually desirelessness.” There is a similar statement in the Caitanya-caritāmṛta (Madhya 19.149):

kṛṣṇa-bhakta — niṣkāma, ataeva ‘śānta’
 bhukti-mukti-siddhi-kāmī — sakali ‘aśānta’

“Because a devotee of Lord Kṛṣṇa is desireless, he is peaceful. Fruitive workers desire material enjoyment, jñānīs desire liberation, and yogīs desire material opulence; therefore they are all lusty and cannot be peaceful.”

Generally there are three classes of living entities afflicted with selfish desire. These are the bhukti-kāmī, mukti-kāmī and siddhi-kāmī. Bhukti-kāmī refers to those ordinary persons who desire money and everything money can buy. Such a primitive mentality is based on the desire to enjoy money, sex and social prestige. When a living being becomes frustrated with this hallucination, he takes to the path of speculative philosophy and analytically tries to track down the source of illusion. Such a person is called mukti-kāmī because he desires to negate material illusion and merge into an impersonal spiritual state, free from anxiety. The mukti-kāmī is also motivated by personal desire, although the desire is somewhat more elevated. Similarly the siddhi-kāmī, or the mystic yogī who desires the spectacular powers of mystic yoga, such as reaching one’s hand across the world or making oneself smaller than the smallest or lighter than the lightest, is also infected by material or selfish desire. Therefore it is said, sakali ‘aśānta.’ If one has any personal desire, whether it be material, philosophical or mystic, he will be aśānta, or ultimately frustrated, because he will see himself as the central object of satisfaction. This egocentric concept is in itself illusory and therefore ultimately frustrating.

On the other hand, kṛṣṇa-bhakta niṣkāma, ataeva ‘śānta’: a devotee of Lord Kṛṣṇa is niṣkāma; he has no personal desire. His only desire is to please Kṛṣṇa. Lord Śiva himself has praised this outstanding quality of the pure devotees of the Lord by stating:

nārāyaṇa-parāḥ sarve
 na kutaścana bibhyati
svargāpavarga-narakeṣv
 api tulyārtha-darśinaḥ

“A person who is devoted to the Supreme Personality of Godhead, Nārāyaṇa, is not afraid of anything. Elevation to the heavenly kingdom, condemnation to hell and liberation from material bondage all appear the same to a devotee.” (Bhāg. 6.17.28) Although the impersonalist philosopher proposes that everything is one, the devotee of the Lord is actually tulyārtha-darśī, or empowered with the vision of oneness. The devotee sees everything as the potency of the Supreme Personality of Godhead and therefore desires to engage everything in the service of the Lord, for the Lord’s satisfaction. Since the devotee does not see anything as dvitīya, or outside the scope of the Lord’s potency, he is happy in any situation. Having no personal desire, the devotee of Kṛṣṇa is actually śānta, or peaceful, because he has achieved the perfection of life, love of Kṛṣṇa. He is actually situated in his eternal constitutional position under the direct shelter and protection of the omnipotent Parameśvara, Kṛṣṇa.

According to Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura, this verse ends the answer given by the first of the nine Yogendras, Kavi, to Mahārāja Nimi’s first question, “What is the highest good?”