Short answers, pulled from the story.
The philosopher Zoroaster simplified the pantheon of early Iranian gods into two opposing forces. Ahura Mazda represented Illuminating Wisdom while Angra Mainyu embodied Destructive Spirit.
Augustine of Hippo defined sin as a word deed or desire in opposition to the eternal law of God in the early fifth century. His definition appeared in Against Two Letters of the Pelagians written during that period.
Hindu concept dharma clearly divided world into good and evil explaining why wars sometimes necessary. Dharmayuddha described wars waged to establish protect righteousness when balance went off.
Carl Jung depicted evil as dark side of Devil in Answer to Job and other works. People tended believing evil existed externally because they projected shadow onto others instead of recognizing internal sources.
Niccolò Machiavelli advised tyrants it far safer be feared than loved within The Prince written in sixteenth century Florence. Treachery deceit eliminating political rivals usage fear offered methods stabilizing prince security power according to his advice.