An Evil Spirit

Man is body, soul and spirit. The soul drives the body but the spirit drives the soul. The soul that sins will die eternally in hell but the soul that obeys God will live for ever. "But it is a spirit in man, And the breath of the Almighty gives them understanding.” Job 32:8

The spirit is given my God, in which also lives our conscience, which naturally tells the difference between right and wrong.
The Spirit of God lives in your spirit(heart) if you have invited Jesus into your heart. He will clean you

“let us draw near with a sincere heart in full assurance of faith, having our hearts sprinkled clean from an evil conscience and our bodies washed with pure water. “Hebrews 10:22