It is generally accepted now that the main purpose of Bhagavad Gita is to induce people to action. Sri Krishna urges all to do their duty sincerely, as per existing laws and without attachment or expectation of results. Here the stress is on KARMA YOGA as the suitable path for advancement of mankind.
What does Karma Yoga mean?
KARMA : The word originated from the root “KRU” meaning do, work, etc. Karma thus means action or work, and not the popular meaning of “fate”. There are two types of Karma- 1) Niskama Karma- work without attachment, which produces no bondage, and 2) Sakama Karma-all work done for some end result, which leads to bondage for the doer. The work may be to maintain your body, meet your official obligations, to upkeep your family, prayers & other religious activities, service to society or many other things. In Gita, the word Karma is used to denote all human activities.
YOGA: This is a much more confusing word. Yoga is generally understood as the activity of breath control or taking different body postures, or the activities mentioned by Pathanjali. But in Gita this word has a much wider and somewhat different meaning.
The word yoga originated from the root “YUJ” meaning joining, timing together etc. This word is used in innumerable places in the Gita with meanings like appropriateness, joining, expertise, attainment etc. The essential meaning of yoga is explained by Sri Krishna himself as “yogah karmasu kausalam” (gita 2:50). Kausalam means a special talent, expertise or skill in doing something. So doing things with expertise is yoga.A yogi is one who does something with expert knowledge or skill.
So KARMA YOGA refers to all human activities performed with concentration, skill and finesse.
The way to liberation is to perform your duties without attachment. In Bhagavad Gita Sri Krishna instructs Arjuna (all of mankind) to do their work most sincerely & with expertise and skill they have masterd, and without any attachment or expectation of rewards.