These stories all teach us about God and Jesus Christ. They show us Jesus’ divine nature and that He has the ultimate authority over everything, including evil. Satan can’t do anything Jesus doesn’t allow him to do. We see this in the story of Job, when Satan asks God for permission to test Job each times before he actually does it.
The fact that Jesus has power over demons offers us hope, and allows us to fully trust in Him. He has the power to set us free from death and Satan’s control over us. Satan came into this world to control us and hand us over into death, but Jesus came into this world to set us free and offer us life. Ultimately, these stories reflect the constant battle between good and evil, and they show us God’s plan for humanity and reflects His kingdom to come. We will one day be set free from all the evil and death in this world for good, and live with God forever.