na hi kaścit kṣaṇamapi jātu tiṣṭhatyakarmakṛt |
kāryate hyavaśaḥ karma sarvaḥ prakṛtijairguṇaiḥ ||3.5||
Indeed, no one ever remains for even a second without performing actions because everyone is forced to perform action by the (three) gunas (sattva, rajas and tamas) born of prakrti.
There is no time when we are free from activity, either voluntary activities like walking, talking, eating, etc or involuntary activities like breathing, blinking, thinking, etc. We are helplessly impelled by an unseen cause which is prakrti to do all types of karma.
Prakrti is the material cause for everything in the creation including our body-mind-sense-complex. Being the product, it carries qualities of its caused. While prakrti has three qualities - guna namely sattva, rajas, and tamas, all its products (everything in this creation) also carry these three qualities. These qualities can't be seen but can be inferred. Just like we know that gold ornaments are made from gold because we inferred from the color, shine, non-rusting qualities of gold. In the subject matter of karma, all actions are impelled by desires. While our mind is born of prakrti which has qualities of sattva, rajas and tamas, their combinations produce certain types of desires, where the expressions of which can be classified according to these three guna. For example an action of giving, when one expecting return while giving, this action is born of tamas; giving for the sake of own satisfaction, this action is born of rajas; and giving because it is just an act which one supposed to do, this action is born of sattva. These three guna impel us to perform action, but I-ātmā is not the doer/enjoyer.
Further Lord Krsna explained the meaning of worship/offering as the attitude of karma-yoga.
yajñārthātkarmaṇo'nyatra loko'yaṃ karmabandhanaḥ |
tadarthaṃ karma kaunteya muktasaṅgaḥ samācara ||3.9||
A person is bound by karma if it is not done as yajña (as an offering to Īśvara). For this reason, Kaunteya (Arjuna)! Being one free from attachment, perform action for the sake of that (yajña).
Yajña means Īśvara. Whatever action to be done for Īśvara is called yajñārtha. For one who is qualified to do karma, but doing action not as worship of Īśvara, for he/she action is bondage. Therefore one should perform karma with the attitude of karma-yoga to be free from bondage of karma.
There are satvic-actions prescribed by śastra as the contribution for the Lord and universe in the form of panca-maha-yajñā:
1. deva-yajñā - certain ritual and prayer towards devatā (divine dignity)
2. pitr-yajñā - ritual for satisfying the ancestors
3. rshi/brahma-yajñā - studying Veda
4. manusya-yajñā - serving people
5. bhuta-yajñā - serving other being like plants, animals, and environment.
Worship is an expression of reverence and adoration. First, one needs to acknowledge the existence of Īśvara who has supremacy over this creation, then worship can be done. From the teaching of Vedānta, one comes to know that nothing in this creation is looked upon as something separates from the Lord. Through worshiping the creation (as Īśvara's manifestation), one is worshiping the creator - Īśvara himself. Then the form of worship can be extended through any being, including one self. Thus the recipient of the worship/offering, the one who does the offering, and the offering itself is one and the same. This is the ultimate devotion which is seeing oneself, the Lord and entire creation as non-duality self (Gītā 7-17). Therefore through yajñā, one is free from bondage of karma.