Through my observation and study of Scripture, I have come to believe, quite confidently, that demons cannot be fallen angels. Now, I know that idea will be rather jarring for some people. It may seem that I am not only challenging a widely held traditional view but also contradicting very clear teachings of the Bible. Well, the idea that demons are not fallen angels certainly contradicts tradition. But in no way does it contradict Scripture.
I want you to picture a tree. See its leaves, branches and stems. Imagine its thick trunk and twisted roots. Allow yourself to see through the dirt and visualize the tree in its entirety, from the highest point to the far tip of its deepest root. Now, let us say that this tree represents your salvation. Only a real tree can bear fruit. But is it the fruit that causes the tree to grow? No, it is the root system that causes it to grow. Good works are the fruit of salvation. They are not the root of salvation.