Traditionally, the concept of the liberation of the soul was related to the abandonment of the life of the world, which is generally considered to be characterized by desire, attachment and ego. Sri Aurobindo points out that bondage and liberation are not defined by the outer actions of the individual, but rather, of the inner response to the action.
“The sign of the immersion of the embodied soul in Prakriti is the limitation of consciousness to the ego. The vivid stamp of this limited consciousness can be seen in a constant inequality of the mind and heart and a confused conflict and disharmony in their varied reactions to the touches of experience.”
Normally the ego is under the sway of the dualities, good and evil, pleasant and unpleasant, attraction and repulsion.
“It is only when, awaking from its immersion in Prakriti, it perceives its oneness with the One and its oneness with all existences that it can become free from these things and find its right relation to this executive world-Nature. Then it becomes indifferent to her inferior modes, equal-minded to her dualities, capable of mastery and freedom; it is seated above her as the high-throned knower and witness filled with the calm intense unalloyed delight of his own eternal existence.”
The Isha Upanishad states: “But he who sees everywhere the Self in all existences and all existences in the Self, shrinks not thereafter from aught. He in whom it is the Self-Being that has become all existences that are Becomings, for he has the perfect knowledge, how shall he be deluded, whence shall he have grief who sees everywhere oneness?” (Sri Aurobindo, The Upanishads, Isha Upanishad 6-7, pg. 21)
This state of consciousness does not require an abandonment of life and action: “The embodied spirit continues to express its powers in action, but it is no longer involved in ignorance, no longer bound by its works; its actions have no longer a consequence within it, but only a consequence outside in Prakriti. The whole movement of Nature becomes to its experience a rising and falling of waves on the surface that make no difference to its own unfathomable peace, its wide delight, its vast universal equality or its boundless God-existence.”
The Isha Upanishad concludes “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.” (Isha Upanishad, 2, pg. 19)
The sign of the liberated soul is the inner equality and the experience of Oneness.
Sri Aurobindo, The Synthesis of Yoga, Part One: The Yoga of Divine Works, Chapter 3, Self-Surrender in Works–The Way of the Gita, pp. 92-93