We have said that this world is one of illusion. God had to offer a correction to our madness that would protect the whole from self-destruction. So we can play our war games in illusion, and they do not affect the Spirit at all. The idea of a great fight between good and evil is a product of an ego-oriented mind that merely wants to see light. That mind is still far from Home.
In the Course, Jesus presents a worldview that bypasses all the complicated theories about ultimate Reality that we have made up and have yet ultimately found to be unsatisfactory. The Course presents a unified worldview, to be believed in its entirety or not at all. Still it is a happy fiction, which Jesus identifies salvation to be. (C-3.2:1) We have come so far into madness that we have very nearly lost our way. The Course highlights the death of our ego as the way to get us out. That is all. But that is enough.