Those who recognise the illusory nature of the forms, forces and actions in the world and wish to find salvation through identification with the Supreme, have often resorted to the simplest response; namely, abandon life and action and the working of desire, focus on the silent, immutable Self of existence, and essentially “cut the knot” of the problem. This approach is the basis of the various meditation or retreat based paths toward salvation.
Others take the approach that action of some sort is necessary, but that there are those actions that are to be considered better than others, and in particular certain types of action, such as undertaking warfare, are to be strictly avoided. Within the context of this implied hierarchy of action, salvation is possible. This is the path that is generally considered to be salvation through “good works”.
The Gita takes an approach that avoids both of these limitations, starting from the standpoint of the Divine purpose in the world rather than from the limited human interpretation of that purpose. In that sense, the Gita amplifies the statement of the Isha Upanishad: “Doing verily works in this world one should wish to live a hundred years. Thus it is in thee and not otherwise than this; action cleaves not to a man.” (Sri Aurobindo, The Upanishads, pg. 19, Isha Upanishad, v. 2)
The Gita makes it clear that Arjuna must act, and that it is not out of personal desire or personal aggrandizement that he must act, but as an instrument of a larger Divine Purpose. As Sri Aurobindo explains: “A violent crisis in the destinies of the race has been brought about not by any blind motion of forces or solely by the confused clash of human ideas, interests, passions, egoisms, but by a Will which is behind these outward appearances. This truth Arjuna must be brought to see; he must learn to act impersonally, imperturbably as the instrument not of his little personal desires and weak human shrinkings, but of a vaster and more luminous Power, a greater all-wise divine and universal Will. He must act impersonally and universally in a high union of his soul with the inner and outer Godhead…, in a calm Yoga with his own supreme Self and the informing Self of the universe.”
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 16, The Fullness of Spiritual Action, pp. 436-437