From the reign of adharma (unrighteousness), the world has to enter the era of Dharma (righteousness). Special effort is called for when you cultivate a crop; no effort is necessary when weeds and wild grass are allowed to grow. The valuable crop of Sahajadharma (innate righteousness) has to be cultivated with all care and attention. When Dharma is practised, adharma will decline by itself. No special exertion is needed for its removal. Dharma, since it is associated with truth, is indestructible. To make the Dharma that has become hidden, visible once again, its practice must be intensified. That is Dharmasthaapana (establishing righteousness). Using Arjuna as an instrument, Lord Krishna brought to light the codes of conduct and modes of thought which were laid down from the very beginning and revived their practice. This is not work that can be carried out by ordinary men. So the universal Lord Himself assumed the task and instructed the world through Arjuna.(Geeta Vahini, Ch 7)