Human beings are bound by dharma which is the backbone of worldly living where the conflict between evil and good prevails. Dharma wins when good triumphs over evil. Commitment to dharma was stronger in the earlier yugas — Krita, Treta, Dwapara — and good and evil were in embodied form, like a Duryodhana or a Ravana. The celestial beings have been symbolic of good and the demons of evil.
In Kali Yuga, there is a perceptible fall in moral values. Moreover, good and evil are no longer distinct and distant but reside in each one of us always as our individual tendencies that manifest as actions. The good and the evil co-exist in each one of us in varying degrees at different times. In the Bhagavad Gita, Krishna explains the divine and demonic tendencies in people to show how the conflict is within oneself between these two, pointed out Sri K. Srinivasan in a lecture.
In the sacred battlefield of Kurukshetra the two armies are assembled. Dhritarashtra asks Sanjaya what the two armies are planning to do. Dhritarashtra displays a strong sense of “I “and “Mine” when he asks Sanjaya what “my sons” and the Pandava side are planning to do. This ego sense represents the evil in us. It prompts us to act in ways that go against the Sastras. The term Pandavas literally refers to the Pandava army and also to the Divine tendencies in human beings. When Krishna comes to Duryodhana’s court as the emissary of the Pandavas, He prefers to eat in Vidura’s hut and rejects Duryodhana’s hospitality since partaking the same will be akin to acting against the Pandavas who are to be sustained. The good nature in us which has to be protected is symbolised by Pandavas. The word Sastra comes from the root Sasana which means rules or tenets. These have to be protected. Upholding the code of dharma is the way to protect it and failing to do so is allowing the evil to triumph. Within each one of us this conflict is constantly taking place.
The universe is sustained by the Supreme Brahman who delegates duties to different forces and beings He has created. The Upanishads state that the sun, moon and the cycle of Time remain committed to His decree.