Human nature is instinctively
Bad. We are prone to act as mere animals when our character isn't improved by culture, education, religion, and good parenting.
"What has come into being in him was life, and the life was the light of all people. The light shines in the darkness, and the darkness did not overcome it”
To society, many human instincts are bad. Discrimination, selfishness, survival of the fittest, non-monogamous all frowned upon by society.