The Vedas, like the Mundaka Upanishad, as well as the Svetasvatara Upanishad, compare the soul and the Supersoul to two friendly birds sitting on the same tree. One of the birds (the individual atomic soul) is eating the fruit of the tree, and the other bird (Krishna) is simply watching His friend. Of these two birds — although they are the same in quality — one is captivated by the fruits of the material tree, while the other is simply witnessing the activities of His friend. Krishna is the witnessing bird, and Arjuna is the eating bird. Although they are friends, one is still the master and the other is the servant. Forgetfulness of this relationship by the atomic soul is the cause of one’s changing his position from one tree to another, or from one body to another. The jiva soul is struggling very hard on the tree of the material body, but as soon as he agrees to accept the other bird as the supreme spiritual master — as Arjuna agreed to do by voluntary surrender unto Krishna for instruction — the subordinate bird immediately becomes free from all lamentations.
The demoniac person, who has no faith in God or the Supersoul within himself, performs all kinds of sinful activities simply for sense gratification. He does not know that there is a witness sitting within his heart. The Supersoul is observing the activities of the individual soul. As it is stated in the Upanishads, there are two birds sitting in one tree; one is acting and enjoying or suffering the fruits of the branches, and the other is witnessing. But one who is demoniac has no knowledge of Vedic scripture, nor has he any faith; therefore he feels free to do anything for sense enjoyment, regardless of the consequences.