Yoga vs. Renunciation
A number of Eastern religions preach a strict form of asceticism which involves learning to renounce action and will. Renunciation becomes a process, then, of casting off worldly possessions and obligations and proceeding on a quest for nirvana, as the Buddha did. But Hinduism, as dictated by the Gita, urges yoga instead of renunciation. Yoga is literally "skill in action," or the process of using selfless action -- action designed only to unite with the divine -- as the true process to achieving enlightenment. For we cannot help but act, says Krishna. It is our nature -- and because of that, we must learn to act in accordance with the divine, not as the result and in service to our own egos, which are nothing more than destructive illusions.
Saatva vs. Rajas
The three gunas, born of the body, offer three different qualities which can either support or infect our lives on Earth. The ideal, or the least destructive guna, is saatva -- which supports harmony, purity, and balance in the body. Rajas is its opponent, born of passion and often a primary driver of ego, anger, greed, and lust. And finally, there is tamas, or disconnection -- a person eagerly clouds themselves in ignorance and darkness to avoid the process of reaching yoga. These three gunas present a person's natural inclinations. As long as a person is aware of which one he is naturally born to, as a result of his karma, then he can slowly move toward saatva and eventually toward a yoga which is free from the burden of the gunas.
Karma vs. Dharma
The terms dharma and karma often get confused by introductory Hinduism students and with good reason -- they are both products of the samsaric cycle of birth and death, but they have entirely different spheres of purpose. Karma is the accumulation of debt of action in the course of a person's samsaric cycle. Every action has a reaction and over the course of a lifetime, if one is accordance with the divine, he will gradually work off his or her karma. If he is acting selfishly and for ego, then he will accumulate more karma to work off. Reborn, each person finds their "dharma" or duty in order to work off this karma. Some are born to wealthy families, others to poor ones, some to spiritual families, others to evil-doing ones. The question isn't what you are born to, but how you use your life to dissolve as much karma as possible in order to end the samsaric cycle.
Proof vs. Faith
One of the more subtle themes in the Gita is the contrast between faith and evidence -- and humanity's inclination to want to "see" something in order to believe it. Indeed, one of the central tenants of Buddhism is that we must believe what we see -- and spend our lives trying to see as clearly as possible. But Arjuna keeps asking for evidence, or practicalities of how to achieve yoga and meditation, and Krishna finally offers him the sight of him in his most powerful form. Why Krishna doesn't demand total faith is an interesting tension in the Gita, and one that requires careful attention.
Theory vs. Action
Arjuna is constantly asking Krishna for pragmatic advice of how to put the Gita into concrete action. This emphasis on action is at the core of the entire work. What Krishna gives Arjuna, then, are clear steps and hierarchies for achieving the path of yoga. First off, he says meditation is the most important element, for meditation allows a focus on the divine that will inform every aspect of one's life. Second, there is selfless service, and finally, though not as powerful, one can also turn to blind renunciation. Krishna sees an enlightenment as a process that requires self-control and self-discipline in a series of concrete steps.
Seen vs. Unseen
Krishna makes the distinction between the seen world and the unseen world -- both products of his divine lila, or play. The unseen world is the purusha, of which all things are born. It is the spiritually unseen realm that informs everything that comes of prakriti, the material world. As humans, we have a tendency to put a primacy only on what we see instead of believing in a higher realm. Krishna wants Arjuna to have faith in the unseen as the guide of all his actions.
Jinana vs. Vijanana
Jinana is knowledge - and Krishna preaches knowledge as the first step towards true nirvana. The self-awareness that comes with understanding the role of the divine in everything we do will help guide a person towards yoga. But this is not enough. Krishna also encourages vijanana, or the act of using jinana in life, as the key to finding spiritual peace. Vijnana is simply yogic action -- or being able to maintain self-awareness at every moment in life -- even at the moment of death.
