Purity of mind is another important divine quality extolled in the Bhagavad Gita. (13.7 and 16.1)
Though we are essentially divine, we mistakenly think we are no more than body and mind. This mistaken notion is the main impurity that creates all other impurities in the mind. It is the greatest obstacle in spiritual life. False identification with body and mind accounts for our selfishness, our misdirected search for lasting happiness among fleeting objects of the senses. However, the Upanishads teach us that eternal bliss and true fulfillment is possible only in the Infinite, in God. The Taittiriya Upanishad says: "He who is self-created [Brahman] is Bliss. A man experiences happiness by tasting that Bliss. Who could breathe, who could live, if that Bliss did not exist in his heart?" (2.7.1)
Purity of mind indicates a mind that has become one with divinity. In that state of divine absorption the mind ceases to be the mind: it becomes one with God. Says Sri Ramakrishna: "God is realized as soon as the mind becomes free from attachment. Whatever appears in the Pure Mind is the voice of God. That which is Pure Mind is also Pure Buddhi; that, again, is Pure Ātman, because there is nothing pure but God."
God is thus the greatest purifier. The ease with which divine thoughts arise in the mind indicates how pure the mind really is. The more we think of God, the more we grow in purity.
Our thoughts are responsible for our actions. Our mental condition determines our character and the quality of our life. The Bhagavad Gita teaches that a controlled mind acts as our friend and helps us to live a moral and spiritual life. An uncontrolled mind, on the other hand, is our enemy and acts against our interests. (6.6)
Says Sri Ramakrishna: "Bondage and liberation are of the mind alone. The mind will take the color you dye it with. It is like white clothes just returned from the laundry. If you dip them in red dye, they will be red. If you dip them in blue or green, they will be blue or green. They will take only the colour you dip them in, whatever it may be....If you are in bad company, then you will talk and think like your companions. On the other hand, when you are in the company of devotees, you will think and talk only of God."
The mind is naturally inclined to focus on sense objects. This tendency gives rise to desires. Desires make it difficult to think of God or give an inward turn to the mind.
Sri Ramakrishna explains the need for purity of mind: "The mind is like a needle covered with mud, and God is like a magnet. The needle cannot be united with the magnet unless it is free from mud. Tears wash away the mud, which is nothing but lust, anger, greed, and other evil tendencies, and the inclination to worldly enjoyments as well. As soon as the mud is washed away, the magnet attracts the needle, that is to say, man realizes God. Only the pure in heart see God."