Yes, God created the demon, but the demon(s) were originally angels that were in with God. When creating a life form a Creator would give it free will to make their own choices. Otherwise they would just be slaves.
Now we know god has foreknowledge so knew some angels and some humans would turn against him. Again free will. He did and does try and convince them otherwise. If they persist in rebellion then they become evil.
Demons by themselves are not such a challenge if you confront them in the name and power of Jesus. But they aren’t stupid creatures either. they are cunning. So they influence other people, especially people close to you: family, so called friends, in the workplace. The demon takes advantage of peoples faults, weaknesses, insecurities and tweaks them. This is the cause of much conflict in the world, both private and nations against nation.
many wars are religious in nature, including the most recent ones. the demon is influencing BOTH sides, even when one or both sides claim to be Christian. The demon also knows this will give Christ a bad name and people will blame God. This goes along with Jesus warning about false prophets and people who come in his name that are false teachers.
Very important verse, and it is hard still to deal with when the demon affects someone close to you: husband, wife, child, parent, inlaws, etc.
Ephesians 6:12
For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.
To paraphrase that it literally means, Our ·fight [conflict; struggle] is not against people on earth [ flesh and blood] but against the rulers and authorities and the powers [or cosmic powers/rulers] of this world’s darkness [L darkness], against the spiritual powers of evil in the heavenly (astral/spirit) world [realm; places].
So while people do have a sin nature, the sin nature is usually provoked by demonic powers. this is the story of Adam and Eve with the fruit…it took an entity to deceive them and influence them, lie to them and get them to turn from Gods way. Once that happened it opened the door for it to happen to everyone.
Ok, so I have been guilty of getting mad at people and not confronting the demon directly as much as should be done. I think everyone goes through this. They SEE the 3D person acting a certain way and that person gets 100% of the blame. Need to sit back for a minute and consider how much demon influence is involved.
The fight must be taken into the spirit realm where the problem originates from.
And…