In many mythologies, human characters are often portrayed as having two distinct sides to their personalities or nature. One side represents good, light, and righteousness, while the other represents evil, darkness, and corruption.

Different mythologies have their own way of depicting the two sides of human character.

In Christianity, it is believed that Adam and Eve were created in God's image, but they fell from grace and became sinful, having two sides of human nature: good and evil.