We have an invisible enemy working behind our visible reality. That visible reality is called the "world" in the Scriptures. This does not refer to the beautiful world that we live in (e.g. the mountains, the sky, the seas, etc.). It refers to the systems and philosophies of the world. We must understand the nature of "this" world as the Bible describes it so that we can understand also why we struggle in taking care of our souls and the souls of others.