The following extracts are from ‘Good and Evil’ by Swami Abhedananda of Ramakrishna Vedanta Math (taken from the Internet).
“Good and evil of this world of duality are unreal, are spoken of by words, and exist only in the mind.” – Bhagavatam, XI, ch. XXII.
“In the voluminous writings of Hindu sages, there is no word that means creation out of nothing. The word, they use, literally means Projection and not creation, answering to the modern idea of evolution. Unlike the Western people of the present day, they had nothing to learn, as they had slowly and gradually discovered the true cause of good and evil, and afterwards explained their mutual relation as clearly as possible.
They said that good and evil are relative terms, one of which cannot exist without the other. What we call good depends upon the existence of what we call evil, and evil exists only in relation to good. Being interdependent terms they cannot be separated. In trying to separate them and to make each stand by itself as independent of the other, we not only destroy their relative and interdependent nature, but also destroy the terms themselves.
The moment we try to separate good from evil, we find this to be true. Evil cannot exist alone. If we try to make evil stand by itself as entirely separate from good, we can no longer recognize it as evil. Consequently, according to the Vedanta philosophers, the difference between good and evil is not one of kind, but of degree, like the difference between light and darkness.
Again the same thing can appear as good and evil under different circumstances. That which appears as good in one case, may appear as evil if the conditions change and the results be different. … … “