Liberation, as the Gita proposes it, was not meant to be an utter abandonment of life, existence, action and enjoyment. Sri Aurobindo describes the Gita’s sense: “…the distinction between the embodied soul subjected to the action of Nature by its enjoyment of her Gunas, qualities or modes and the Supreme Soul which dwells enjoying the Gunas, but not subject because it is itself beyond them, are the basis on which the Gita rests its whole idea of the liberated being made one in the conscious law of its existence with the Divine. That liberation, that oneness, that putting on of the divine nature, sadharmya, it declares to be the very essence of spiritual freedom and the whole significance of immortality.”
The Gita makes a distinction between the soul that takes and uses a physical form, and the form itself. Forms are ever in flux and undergoing change. Just as we change clothes when they are worn out, dirty or no longer serve the purpose for the proposed action, so the soul changes its physical form through the process of rebirth and takes up its evolutionary development of consciousness, until it eventually reaches the state where it has attained liberation through conscious oneness with the divine nature.
“…the soul bearing the body comes to a Pralaya”, to a disintegration of that form of matter with which its ignorance identified its being and which now dissolves into the natural elements. (Pralaya means dissolution, or disintegration, usually used in the sense of the universe undergoing a cessation or hiatus before re-emerging, but also used by the Gita to describe the individual soul’s putting off of bodies before taking on new ones.)
“But the soul persists and after an interval resumes in a new body formed from those elements its round of births in the cycle, just as after the interval of pause and cessation the universal Being resumes his endless round of the cyclic aeons. This immortality in the rounds of Time is common to all embodied spirits.”
This is however, not the ultimate sense that the Gita portrays, but rather a sort of successive recurrence. Immortality is not of the body, but of the soul, and it only truly comes about when the soul has achieved that state of awareness that identifies itself with the supreme status of the Spirit. “Liberation, immortality is to live in this unchangeably conscious eternal being of the Purushottama.”
“The divine Purshottama, who is the supreme Lord and supreme Brahman, possesses for ever this immortal eternity and is not affected by his taking up a body or by his continuous assumption of cosmic forms and powers because he exists always in this self-knowledge. His very nature is to be unchangeably conscious of his own eternity; he is self-aware without end or beginning.”
“But to arrive here at this greater spiritual immortality the embodied soul must cease to live according to the law of the lower nature; it must put on the law of the Divine’s supreme way of existence which is in fact the real law of its own eternal essence. In the spiritual evolution of its becoming, no less than in its secret original being, it must grow into the likeness of the Divine.”
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 14, Above the Gunas, pp. 407-408