Developing equanimity that remains steady under all circumstances whether favourable or hostile is a paramount teaching of the Gita. At the same time, cultivation of equanimity is indispensable for practising Karma Yoga. Attainment of liberated status of soul that remains unmoved by what happens in the outer life is the end of all yogic pursuits. This free status of self is attained when one develops the power to remain immersed in his inner life completely surrendered to the Divine. In case of Karma Yoga, one can perform actions in life as given to him by the Divine without being distracted by the outer life disturbances from his immersion in soul life.
Equanimity is difficult to attain, given constitution of human nature. We, the humans, are egoistic, emotional beings. We principally deal with the world emotionally as the power of reasoning is still a very weak force in our life.
However, as we progress in yoga our detachment with life deepens. As we grow increasingly detached, the normal reactions to the life situations fall off from our nature and consequently, equanimity becomes stronger in us. The Gita says that true equanimity comes straight from the soul. Equanimity attained through mind is unstable.
Karma Yoga in its true sense cannot succeed if we fail to attain the free status of our self that is ever unmoved by the caprices of outer life. This free status of self is not affected in the least even if we are dynamically involved in multifarious activities of life.
The Gita is emphatic on the point that one cannot do yoga, much less Karma Yoga unless one acquires the power of conquering life’s normal reactions to pleasurable and painful situations, suffering and enjoyment, love and hatred etc. These are the dualities of life and one who practises yoga must be free from these dualities and relativities and remains settled unshakably in the yogic consciousness that does not grumble while suffering and does not rejoice while enjoying.