Definition - What does Evil mean?
Evil is most generally defined as the absence or opposite of what is considered good. It is often linked to concepts of morality, where things which are morally wrong are regarded as evil.
Although the concept of evil is not as predominant in yogic philosophy as in other philosophies and religions, it does draw some influence from Buddhist and Hindu perceptions of evil. According to Buddhism, oneness can be achieved by recognizing that the duality of good and evil is only an illusion. Hindu texts also refer to a balance between good and evil.
Yogapedia explains Evil
Yogic analogies to the concept of evil can be found in the causes of suffering: for example, desire, hate and delusion. In that sense, evil can be anything that is an obstacle to happiness and spiritual liberation (moksha). The intention of Buddhism and the path of yoga is to overcome such obstacles and be free from suffering.
One theme found in the Bhagavad Gita, an ancient Hindu and yogic sacred text, is the balance between good and evil. Divine incarnations intervene to restore this balance when it has fallen out of equilibrium. The text emphasizes the good and evil of actions, rather than the idea of people being inherently good or evil.
Some yogic teachers argue that there is no real concept of evil in yoga, in the sense that there is no dark force at work. Yoga sometimes teaches, instead, that the only darkness or evil is that which exists in the mind and that this can be overcome by allowing the Divine to illuminate the mind. Thus, meditation or yoga practice can be ways to counteract evil.