God uses demons to undo the design of the father of demons. God uses Satan to defeat the purposes of Satan. This is not exceptional — like, “Whoa, that’s an eccentric view.” This is not exceptional. He did it with Job. He did it with Judas. He did it with Paul. He’ll do it with you.
What happened when Satan entered into Judas? He handed Jesus over to be crucified. What happened when Jesus was crucified? I’ll read it to you. This is Colossians 2:15: “He disarmed the rulers [the satanic rulers] and authorities and put them to open shame, by triumphing over them in him.”
The death of Jesus disarmed Satan in his warfare against God’s people. It stripped him of his one damning weapon: unforgiven sin. “Who shall bring any charge against God’s elect? It is God who justifies. Who is to condemn? Christ Jesus is the one who died” (Romans 8:33–34). None of your accusations stick anymore, Satan. You have been stripped of the one weapon with which you could damn us: unforgiven sin. No more.
When Satan entered Judas, he signed his own death warrant with the blood of Jesus. The suicide of Judas was symbolic of the suicide of Satan. Over and over again in the history of God’s people, God shames Satan as a suicidal fool in the service of salvation — over and over. Praise God. That’s what he’s doing here: putting Satan to work for Paul’s protection from pride; putting the father of all pride to work to destroy pride in his apostle. I like the way God works.