Krsna begins the chapter with precise definitions of Brahman, Atman and action. He then goes on to highlight the power of thought. You are a product of your thoughts. You sculpt your own future by guiding your thoughts towards your goal. If the goal is worldly, you remain caught up in the vagaries of the world. However, if you have invested your thoughts in the spiritual ideal, you break free from the cycle of birth and death to merge with Brahman.
The spiritual journey begins by redirecting your thoughts from material pursuits to spiritual aspirations. Once this is done, make an effort to master the senses. Follow the practices of Karma Yoga (Path of Action), Bhakti Yoga (Path of Devotion) and Jnana Yoga (Path of Knowledge). It is through these practices that the mind becomes calm and free from desire. With a steady mind purified of desire practise meditation under intellectual supervision. You will transcend the world and attain Self Realisation.
As an individual’s personality comes alive during the day and becomes dormant at night, the universe also goes through the cycle of manifestation and folding back into the unmanifest state. This macrocosmic cycle is referred to as the day and night of Lord Brahma where the entire cosmos comes into creation during the day and all creation goes back into the unmanifest form at night. Brahma’s day lasts for 4.32 billion earthly years and his night is of the same duration. Brahman is beyond this macrocosmic cycle.
Finally, Krsna offers three options to humanity – the path of return, non-return and direct liberation. If you perform desire-driven noble actions, you go to heaven after death to enjoy the fruits. Once this punya (merit) is exhausted, you return to the mortal world. This is the path of return. If you aspire for Realisation but stray into actions motivated by good desires while performing the spiritual practices, you get liberation in phases. You go to heaven, enjoy the heavenly pleasures that accrue to you and then proceed to the fourth plane of Consciousness.