"If it be faithful to God (the soul of man), it will reflect His light, and will, eventually, return unto him. If it fail, however, in its allegiance to its Creator, it will become a victim to self and passion, and will, in the end, sink in their depths." Baha'u'llah (Gleanings pg 158)
The Baha'i writings speak of Satan and demonic forces but not existing as an evil personage, but rather as our ego and animal nature which is ever ready to do battle against God. Baha'u'llah has given us God's instructions for this day to fortify our spiritual side so we can win that battle.