To give a short answer to this question, i ask another: Does the creation account in Genesis mention God creating darkness? No, darkness already existed before God created light (Genesis 1:2-3), God created light, darkness is absence of light.
We see this pattern repeatedly in the world, for example: Cold is not ”something”: it is lack of heat, drought is simply the absence of moisture, and ignorance is the lack of knowledge.
So it is clear that evil is simply the absence of the good things that originate from God, such as: love, holiness, unity, truth, harmony, health, peace, life, pleasure, faith, order, etc… in the absence of these things you have: hate, unholiness, disunity, fallacy, disharmony, sickness, war, death, pain, fear, disorder, etc… which all fall under the category of evil.
A natural disaster like a flood is considered something evil, but water is not in itself evil, neither is rain or any of the ingredients that make it a disaster, the fact is a flood and other natural disasters result from a lack of balance, order and harmony in environmental factors.
The Bible says God created all things, and all things were good. Evil isn’t good, therefore God didn’t create evil. If God created all things, and God didn’t create evil, then evil is not a thing, but a lack of something.
Notice also that much later on in the Bible God speaks of creating darkness, see: Isaiah 45:7, Psalm 104:20, Amos 4:13. But since light was already created in these accounts, creating darkness would simply involve excluding or removing the light. To speak of creating darkness, implies that light already exists and is present. Just as speaking of creating a vacuum in a tube, implies that something other than a vacuum is already in the tube. So to remove light is to create darkness.
So when God says he creates evil in Isaiah 45:7, It is God removing the good things, such as His blessings of peace, provision, protection etc… when God curses something, he simply removes His presence and blessings. Following this train of thought, sin could be defined as a thought, action or state of the soul that lacks love, truth, faith, holiness etc…
Evil is not an illusion of the mind or soul as some may believe. Evil is very real and its power is very real, yet it is nothing. You may ask “how can nothing have power?” A vacuum is nothing but a void, yet it has great power to pull things towards it.
Satan exists and is very real, he is simply a good angel that has turned bad, he is a spiritual being that is empty of all things godly, Satan’s kingdom of darkness is like a spiritual vacuum, that seeks to suck humanity of life, love, the light of truth. etc.