Dualism is a doctrine that the universe is under the dominion of two opposing principles one of which is good and the other evil.
Let me say that dualism is a false doctrine because it assumes that all affliction, calamity, adversity, poverty, and trouble come directly from Satan.
No doubt, much of the adversity we face does derive from Satan's realm of darkness, but the fact is all adversity is the result of the fall of mankind from his original state with God.
The theory that all adversity is Satanic is contradicted by the experience of almost all the Apostles, martyrs and great leaders of the Church, who saw adversity as a means to see God glorified. The Word of God teaches us that the testing of our faith produces steadfastness.
James 1:2-4 ESV Count it all joy, my brothers, when you meet trials of various kinds, (3) for you know that the testing of your faith produces steadfastness. (4) And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing.
Adversity is evil only if we permit Satan to defeat us with it. On the other hand, there is victory in Christ out of all life's experiences. All of us, saved and lost, have faced, is currently facing, and will face adversity of some kind.
God used (or turned around) trouble in Paul's life for His purpose, but three times the Apostle uses the word "DELIVER." Paul said, writing to the Corinthian church:
2 Corinthians 1:8-10 ESV (8) For we do not want you to be unaware, brothers, of the affliction we experienced in Asia. For we were so utterly burdened beyond our strength that we despaired of life itself. (9) Indeed, we felt that we had received the sentence of death. But that was to make us rely not on ourselves but on God who raises the dead. (10) He delivered us from such a deadly peril, and he will deliver us. On him we have set our hope that he will deliver us again.
In 2 Cor.1:8-10 notice the use of the word "delivered." We see Paul addressing all three tenses, past, present and future adversity.
There are opposing forces in the world and the believer is in the midst of the battle, but we are on the winning side because...
1 John 4:4 ESV Little children, you are from God and have overcome them, for he who is in you is greater than he who is in the world.
John 16:33 ESV I have said these things to you, that in me you may have peace. In the world you will have tribulation. But take heart; I have overcome the world."