SB 11.2.6

bhajanti ye yathā devān
 devā api tathaiva tān
chāyeva karma-sacivāḥ
 sādhavo dīna-vatsalāḥ
Word for word: 
bhajanti — worship; ye — they who; yathā — in which way; devān — the demigods; devāḥ — the demigods; api — also; tathā eva — just in that way; tān — them; chāyā — in a shadow; iva — as if; karma — of material work and its reactions; sacivāḥ — the attendants; sādhavaḥ — saintly persons; dīna-vatsalāḥ — merciful to the fallen.
Translation: 
Those who worship the demigods receive reciprocation from the demigods in a way just corresponding to the offering. The demigods are attendants of karma, like a person’s shadow, but sādhus are actually merciful to the fallen.
Purport: 

The words chāyeva karma-sacivāḥ are significant here. Chāyā means “shadow.” The shadow of the body precisely follows the movements of the body. The shadow has no power to move in a way different from the movement of the body. Similarly, as stated here, bhajanti ye yathā devān devā api tathaiva tān: the results the demigods award to living beings correspond exactly to the living beings’ actions. The demigods are empowered by the Lord to follow precisely the particular karma of a living entity in awarding him happiness and distress. Just as a shadow cannot move independently, the demigods cannot punish or reward a living being independently. Although the demigods are millions of times more powerful than the human beings on earth, they are ultimately tiny servants of God whom the Lord allows to play as the controllers of the universe. In the Fourth Canto of Śrīmad-Bhāgavatam, Pṛthu Mahārāja, an empowered incarnation of the Lord, states that even the demigods are subject to punishment by the Lord if they deviate from His laws. On the other hand, devotees of the Lord such as Nārada Muni, by their potent preaching, can interfere in the karma of a living being by persuading him to give up his fruitive activity and mental speculation and surrender to the Supreme Personality of Godhead. In material existence, one works hard under the bondage of ignorance. But if one becomes enlightened by association with a pure devotee of the Lord, one can understand one’s actual position as an eternal servant of God. By rendering such service, one dissolves his attachment to the material world and the reactions of his previous activities, and as a surrendered soul he is endowed with unlimited spiritual freedom in the service of the Lord. In this regard, the Brahma-saṁhitā (5.54) states:

yas tv indragopam athavendram aho sva-karma-
 bandhānurūpa-phala-bhājanam ātanoti
karmāṇi nirdahati kintu ca bhakti-bhājāṁ
 govindam ādi-puruṣaṁ tam ahaṁ bhajāmi

“I adore the primeval Lord, Govinda, who burns to the root all the fruitive activities of those imbued with devotion. For those who walk the path of work — no less for Indra, king of the demigods, than for the tiny insect indragopa — He impartially ordains the due enjoyments of the fruits of activities in accordance with the chain of works previously performed.” Even the demigods are bound to the laws of karma, whereas a pure devotee of the Lord, having completely given up the desire for material enjoyment, successfully burns to ashes all traces of karma.

In this regard, Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura has commented that unless one is engaged as a surrendered soul in the devotional service of the Lord, he cannot actually be considered niṣkāma, or free from all personal desire. Sometimes a materialistic person will engage in charity or altruistic activities and in this way consider himself a selfless worker. Similarly, those who engage in mental speculation with the ultimate goal of merging into the impersonal Brahman aspect of the Lord also advertise themselves as being selfless or desireless. According to Śrīla Bhaktisiddhānta Sarasvatī, however, such karmīs and jñānīs, while busy in their so-called “selflessness,” are in fact servants of lusty desires. In other words, they have not perfectly understood their position as eternal servants of God. The altruistic karmī falsely considers himself the best friend of humanity, although he is unable to give actual benefit to others because he is ignorant of the eternal life of bliss and knowledge beyond the temporary hallucination of material existence. Similarly, although the jñānī proudly declares himself God and invites others to become God also, he neglects to explain how the so-called gods have come to be bound by the laws of material nature. Actually, the attempt to become God is based not on love of God but on the desire to take the same status as God. In other words, the desire to be equal in all respects to the Supreme is simply another materialistic desire. Therefore the karmīs and jñānīs, because of their dissatisfaction in artificially trying to fulfill their own desires, can show no actual mercy to the fallen souls. In this regard, Śrī Madhvācārya has quoted the Uddāma-saṁhitā:

sukham icchanti bhūtānāṁ
 prāyo duḥkhāsahā nṛṇām
tathāpi tebhyaḥ pravarā
 devā eva hareḥ priyāḥ

Ṛṣis want happiness for all beings and are almost always incapable of tolerating the unhappiness of men. Nevertheless, the demigods are superior because they are very dear to Lord Hari.” But although Śrīla Madhvācārya has placed the demigods in a higher position than the merciful ṛṣis, Śrīla Jīva Gosvāmī has stated, sādhavas tu na karmānugatāḥ: the sādhus are actually better than the demigods because the sādhus are merciful regardless of the pious or impious acts of the conditioned souls. This apparent disagreement between Madhvācārya and Jīva Gosvāmī is resolved by Bhaktisiddhānta Sarasvatī Ṭhākura, who points out that in the statement by Śrīla Madhvācārya, the word ṛṣi, or “sage,” indicates the so-called sādhus or saintly persons among the karmīs and jñānīs. Ordinary fruitive workers and speculative philosophers certainly consider themselves to be at the summit of pious morality and altruism. However, since they are ignorant of the supreme position of the Supreme Personality of Godhead, they cannot be considered equal to the demigods, who are all devotees of the Lord and aware that all living beings are eternal servants of the Lord. Even such demigods, however, cannot be compared to the pure devotees such as Nārada. Such pure devotees are empowered to award the highest perfection of life to both pious and impious living beings, who have only to follow the orders of such pure devotees.