After establishing the practical superiority of action-yoga over knowledge-yoga, Krishna further elaborates on action-yoga. We (tvaṁ) should perform (kuru) our prescribed (niyataṁ) action (karma), for action (karma) is surely (hy) better (jyāyo) than inaction (akarmaṇaḥ). Furthermore (ca), we (te) cannot (na) even (api) carry out (prasidhyed) basic bodily maintenance (śarīra-yātrā) without action (akarmaṇaḥ). (BG 3.8) So, working is better than inertia. Is any prescribed action equally eligible for the elevation of consciousness? Other (anyatra) than action (karmaṇo) for the sake of offering to Vishnu (yajñārthāt), this is (ayaṁ) a world (loko) of bondage by reaction to action (karma-bandhanaḥ). We should perform (samācara) our action (karma) for His satisfaction (tad-arthaṁ) free from attachment (mukta-saṅgaḥ). (BG 3.9) Lord Krishna clearly advises us to perform our prescribed duty (in the spirit of sacrifice) for the pleasure of Lord Vishnu (non-different from Lord Krishna).
At the beginning of creation (purā), upon creating (sṛṣṭvā) generations (prajāḥ) along with sacrifices for Vishnu (saha-yajñāḥ), the Lord of all creatures (prajāpatiḥ) pronounced [a blessing] (uvāca), “By this [process of sacrifice] (anena), may you become prosperous (prasaviṣyadhvam). May this (eṣa) become (astu) the harbinger of desired enjoyment (iṣṭa-kāma-dhuk) for you (vo). (BG 3.10) The demigods (devān), being pleased (bhāvayatā) by this [sacrifice] (anena), they (te devā) will please (bhāvayantu) you (vaḥ), and by thus pleasing (bhāvayantaḥ) one another (parasparaṁ), you will achieve (avāpsyatha) the ultimate good (śreyaḥ param). (BG 3.11) The demigods (devā), being pleased by your offering of sacrifice (yajña-bhāvitāḥ), will certainly (hi) award (dāsyante) you (vo) the desired enjoyments (iṣṭān bhogān). One (saḥ) who (yo) enjoys (bhuṅkte) the gifts (dattān) given by them (tair) without offering them back (apradāyaibhyo) is only (eva) a thief (stena). (BG 3.12) Eating (āśinaḥ) the remnants of sacrifice (yajña-śiṣṭa), the saintly devotees (santo) are released (mucyante) from all sins (sarva-kilbiṣaiḥ). But (tu), the sinful beings (pāpā), who (ye) cook (pacanty) for themselves (ātma-kāraṇāt), they (te) eat (bhuñjate) sin (aghaṁ). (BG 3.13)”
Thus, Lord Vishnu created the living entities, the demigods (or the cosmic managers who are responsible for managing specific departments within the material world), and prescribed a process of sacrifice for everyone’s happiness and prosperity. No one can live without eating. The simplest way to practice karma yoga is to offer our food to Lord Krishna before consuming it. When we accept the remnants (also referred to as prasadam), we become purified of sins and move closer to liberation from material bondage.
There is a symbiotic relationship between the living entities and the demigods centered around a cycle of sacrifice. The blessing from the Lord of all creatures and the Lord of sacrifice continues as follows.
“All living beings (bhūtāni) derive their sustenance (bhavanti) from food (annād); Food (anna) comes into being (sambhavaḥ) from rain (parjanyād). Rain (parjanyo) comes (bhavati) from sacrifice (yajñād), and sacrifice (yajñaḥ) is born of action (karma-samudbhavaḥ). (BG 3.14) Know (viddhi) that action (karma) is prescribed in the Vedas (brahmodbhavaṁ), and the Vedas are directly manifested from the Supreme Brahman (brahmākṣara-samudbhavam). Therefore (tasmāt), the all-pervading (sarva-gataṁ) Brahman (brahma) is eternally (nityaṁ) situated (pratiṣṭhitam) in sacrifice (yajñe). (BG 3.15)”
One who (yaḥ) does not adopt (nānuvartayati) this established (evaṁ pravartitaṁ) cycle (cakraṁ) [of sacrifice] in this life (iha) leads a sinful life (aghāyur) of sense gratification (indriyārāmo). Such a person (sa) lives (jīvati) in vain (moghaṁ). (BG 3.16)
The Supreme Lord gives us the Vedas (the body of complete knowledge). The Vedas prescribe duties and when the duties are performed in a mood of sacrifice, we get rain, which is the basis for food production. When one offers the food to the Supreme Brahman (Krishna) with feelings of gratitude and partakes in the remnants, one becomes prosperous, purified, and happy. Without this spirit of sacrifice, whatever we do in this material world becomes the cause of our bondage and our life becomes filled with sin.