The following are exerts from my book, The Wisdom Teachings of the Bhagavad Gita.
Chapter 3 begins with Arjuna being confused about why Krishna glorifies jnana yoga (“knowledge” yoga) but suggests he do karma yoga (“action” yoga). Arjuna has decided he no longer wishes to participate in the war, so he’s testing the waters to see if choosing the life of a renunciate is an option. If it is, in the tradition of sannyasa (the renunciate lifestyle), he would be absolved of his duties and be able to pursue moksha (spiritual liberation) alone.
If as you say knowledge is better than action, then why push me to do this horrible deed? You say one thing, and then another. You must give me a definitive answer, knowledge or karma, so I will know exactly what must be done to gain liberation. (3.1)
Arjuna’s question is a legitimate one. Krishna answers his question by explaining the two different lifestyles that devotees may choose from: life as a karma yogi (active and social) or life as a sannyasi (contemplative and secluded). One often hears Vedanta described as the “pathless path.” The reason for this is because you already are what you are seeking. You are the path, but just haven’t realized it yet. Nevertheless, there are two options in regard to lifestyle choices, but because of Krishna’s indirect response to Arjuna’s question, it’s unclear what Krishna recommends at first.
Regardless of whether or not one should be a karma yogi or a sannyasi, karma yoga (the practice, not the lifestyle) is to be understood as preparation for jnana yoga (“knowledge” yoga). The matter of karma yoga versus knowledge yoga may also be viewed as a question of maturity. Until the seeker is mature enough to discover the freedom that is their true nature, they focus on karma yoga. Either way, karma yogais what one establishes in order to cultivate a mind that is able to progress to Self-knowledge. It’s a means of purifying the mind in preparation for the knowledge.
Krishna isn’t about to recommend that Arjuna become a sannyasi because he doesn’t believe Arjuna has the temperament for it. Arjuna has too many irons in the fire to join the life of a sannyasi. His disposition is one of activity, not quiet seclusion. And although Arjuna has already experienced what it’s like to give up everything and live in the forest (from his time before the war, being forced into exile), most of that time was spent holding resentment and meditating on the injustices of his evil cousin, Duryodhana.
Throughout the Gita, Krishna suggests Arjuna lead a life of karma along with the pursuit of knowledge. But whether to choose the life of a renunciate or a life of someone who is active in society is really just a question of one’s disposition—in short, it doesn’t much matter and sannyasa isn’t a requirement for reaching moksha.
Even as a person involved in the busyness of life, we can still carve out some time everyday for study and contemplation if freedom is what we want. Also, the simple life of a sannyasi with its renunciation of activities, isn’t so easy—especially for one who still harbors attachments. For a sannyasi, there is no field wherein to help neutralize one’s binding likes and dislikes. It’s for this reason that the lifestyle of sannyasa is not recommended for most seekers. (That said, it can be advantageous to experience short spans of sannyasa in order to be closer to the teachings and experience a more purified mind—for example, by going on a silent retreat.)
…One benefit of karma yoga is that it allows the seeker who is active in everyday life, the opportunity to diminish their binding likes and dislikes through the eventual insight that pursuing them is unsatisfactory or even, painful. For some people this might mean climbing the corporate ladder and making a lot of money only to find that once they have everything, they are still bothered by a feeling of poverty. Or maybe it means experimenting with being a complete glutton before waking up to the futile nature of samsara. Unless you’re born a contemplative person, committing to a life of sannyasa with bottled-up attachments is only a recipe for disaster. It’s better to remain in the daily grind where at least you can learn from your attachments and aversions without experiencing serious symptoms of withdrawal.
Furthermore, sannyasa is often something that evolves naturally with age and exposure to Self-knowledge. As we get older and wiser, we naturally become more contemplative and wish to distance ourselves from the ways of the world. Thus, sannyasa is not a lifestyle we must adopt in order to have spiritual success.
Moksha that is gained by sannyasis is also reached by karma yogis. The one who sees knowledge and karma yoga as one, sees the truth. (5.5)
Knowledge and karma yoga are seen as one because both eventually lead to the same truth and because you can’t have one without the other.
Nevertheless, in Chapter 18, Krishna provides a list of what might qualify someone for sannyasa:
The one who endowed with a clear mind, controlling the body-mind-sense complex with firm resolve, abandoning the sense objects, such as sound, etc., and abandoning attachment and aversion…
…dwelling in solitude, eating lightly, whose speech, body and mind are mastered, who is frequently engaged in contemplation, who has developed freedom from longing…
…who has foresaken the misplaced ‘I’ sense, power, excessive pride, binding desire, anger, and ownership of external things; who is free from the notion of ‘mine’ of even their own body, etc. and who is tranquil; is worthy of the knowledge of Brahman being oneself. (18.51 - 53)