Where the Gita begins to differ from the traditional yogic path of renunciation is the form of renunciation called for by the Gita and the different end result that the Gita calls forth.
In the traditional path of sannyasa, the goal is clearly the abandonment of the active life and total immersion in the inner world of the Spirit. Sannyasa works to cut off the mind and the senses from their objects and leads to stillness and deep meditation, and eventually a breaking off of the relation of the Soul with the outer nature.
The Gita’s method however has the seeker remaining in the world of action, experiencing the sensations and relating to the objects of the senses, but doing so in a state of inner renunciation, such that the attachment based on desire is given up, so that a state of pure equality of soul is attained with neither liking nor disliking, attraction or avoidance.
Sri Aurobindo describes the Gita’s method: “There is to be vairagya, not in the common significance of disgust of life or distaste for the world action, but renunciation of raga, as also of its opposite, dvesa. There must be a withdrawal from all mental and vital liking as from all mental and vital disliking whatsoever. And this is asked not for extinction, but in order that there may be a perfect enabling equality in which the spirit can give an unhampered and unlimited assent to the integral and comprehensive divine vision of things and to the integral divine action in Nature. A continual resort to meditation…is the firm means by which the soul of man can realise its self of Power and its self of silence. And yet there must be no abandonment of the active life for a life of pure meditation; action must always be done as a sacrifice to the supreme Spirit.”
The renunciation called for in the Gita “…is a preparation rather for the turning of our whole life and existence and of all action into an integral oneness with the serene and immeasurable being, consciousness and will of the Divine, and it preludes and makes possible a vast and total passing upward of the soul out of the lower ego to the inexpressible perfection of the supreme spiritual nature, para prakrith.
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 21, Towards the Supreme Secret, pp. 516-517