Heaven or better next life is not just the only reason for people to commit to their own duties according to varna and stage of life, there is another reason for it. The same karma can be converted into yoga if it is not done for better birth or going to heaven or for gaining anything that is to be enjoyed later, but for what I will get out of it now, in this life. That is what he is going to talk about now.
sve sve karmaṇyabhirataḥ saṁsiddhiṁ labhate naraḥ ।
svakarmanirataḥ siddhiṁ yathā vindati tacchṛṇu ॥ 18-45॥ A man who delights in his own duty gains success. Listen to how one devoted to his own duty, finds success.
sve sve karmaṇyabhirataḥ - a person who is totally involved in his own duties with commitment and enjoyment. He not only experiences satisfaction that comes from doing what he is supposed to do, he is happy in what he does and does not want to do somebody else’s job. If we still think other people’s jobs are better, it means there is no satisfaction in oneself. If one is not satisfied with oneself, it means he is not successful in his life no matter what he does. Success does not depend on how people and society look at me, but my own satisfaction determines how successful I am. This satisfaction is a foundation for one to be aware that happiness is centered in oneself, then only one has the desire to gain the knowledge of ātma.
Since we don’t have a functional varna-āsrama system today, the interpretation of the world sve sve karmaṇyabhirataḥ should be in keeping with exactly what is available right now, my role in the society, family, etc. What is expected of me now, I just do, and enjoy doing it. The one who lives his life doing his own duty with commitment and satisfaction gains success in terms of clarity of the mind, and once he has a prepared mind, there is no hindrance for him to gain knowledge, and thereby, moksa. Now how does he do it? Next, Lord Krsna says.
yataḥ pravṛttirbhūtānāṁ yena sarvamidaṁ tatam ।
svakarmaṇā tamabhyarcya siddhiṁ vindati mānavaḥ ॥ 46॥ Through one’s duty, worshipping Him from whom is the creation of the beings, by whom all this is pervaded, a human being gains success.
Why by worshiping Him (Īśvara) - tamabhyarcya, we gain success - siddhiṁ in the form of clarity of the mind, qualification for the knowledge of ātmā, which is the success or fulfilment of a human life? To understand this, we need to see what is Īśvara and what is worship? Īśvara is not a creator of the universe who is sitting there and rules over our lives. He is the one from whom the entire universe comes to its being - yataḥ pravṛttirbhūtānāṁ, it means He is the intelligent cause. Just like we say a pot comes from the pot maker. But there is another clause here, yena sarvamidaṁ tatam - by whom all this is pervaded. Īśvara is not only the maker, but also the material cause, then only He can pervade the creation, a creation which is non-separate from its material cause. And that cause is not inert but conscious because knowledge is only there for a conscious being, therefore it is also an efficient cause, the maker.
When we usually talk about the material cause for this changing universe we say that is māyā which is endowed with three guna. Because a changing universe can’t come from something which is changeless. Therefore māyā is said to be parināmi-upādāna-kārana - the material cause that undergoes change, and it is mithyā. It is mithyā because when the creation is being analysed, it doesn’t have any basis at all. Everything just reduces until all that left with is mere words, and they keep disappearing too, because when the object is gone, the name is also gone. Only sadvastu Brahman remains as the very is-ness of every object I analysed.
That cause is a power inherent in Brahman, which we call māyā. Brahman with māyā power is what we call Īśvara because with reference to creation he is both th e efficient and material cause which does not undergo any change - abhinna-nimitta-upādāna-kārana.
Now how to worship Īśvara? Here we are not talking about general worship as puja, even though it is one form of worship. To worship means to invoke Īśvara. When you want to catch someone’s attention, you don’t need to touch the entire person, what you need to do is to touch his little finger. The little finger becomes only a nimitta - instrument where you can invoke the whole person. By the mere presence of Īśvara everything takes place. When the whole creation is Īśvara’s form, which part should you touch to invoke Him? Not only that, the creation being not separated from Īśvara, all the various laws, known and unknown, are also non-separated from Īśvara. Therefore by conformity with the law of dharma, doing one’s own duty in a given time and given situation, are worshipping Īśvara. Whenever I do what is appropriate, I connect myself with Īśvara. We don’t want to be devotee only during puja, but when I am relating to others, as parents, friends, members of society, through duty I am always a devotee who do my parts, relate with any aspects of Īśvara.