Evil is not something that has a life of its own, rather, it is a corruption of a perfect creation.
Evil is the addition of corruption that caused perfect to be imperfect. Good has always existed but is restricted – good is something less perfect because evil co-exists. Both exist, but neither is an entity.
Evil is a perversion of good. Evil does not have essence of its own – it is not a thing of substance in itself. Evil is not an entity but a corruption of an entity, and in this case, creation. Pain, crime, lust, ego, death, aggression, weeds, pests, etc., are all manifestations of a corrupted creation, along with extreme weather and earthquakes… and suffering.
God is more than good. God is perfect righteousness. God created a perfect creation of spirit beings. By the negative volition of satan, evil entered the spirit realm. By the negative volition and disobedience of Adam, humanity fell. So, both creations became corrupted.
What defines evil? What defines good? You cannot determine if there is good or evil, nor can you differentiate between either, unless there is an absolute standard.
— C. S. Craig, January 2008