The truth of the doctrine of angelic and demonic powers is that there are supra-individual structures of goodness and supra-individual structures if evil. Angels and Demons are mythological names for constructive and destructive powers of being, which are ambiguously interwoven and which fight with each other in the same person, in the same social group, and in the same historical situation. They are not beings but powers of being dependent on the whole structure of existence and involved in the ambiguous life.Of all the posts I have written in this blog, none has received more google hits than my post on "Fighting Demons". I wonder what all those people are looking for, and I'm not sure how I'm supposed to feel about this interest. I myself like the language of demons, and I use it much the way Tillich describes here: as supra-individual structures of evil. I encounter these all the time - in university administration, in politics at all levels, in the economical systems, sometimes even i social inter-relationships. It is an extremely dynamic way to look at reality, and I can see that pre-enlightenment people found this language useful. As I write in my post about demons, there is no reason to believe that people back then was more superstitious than they are today.
Systematic Theology II, 40.
In Tillich's system the angelic powers of being have a curious role. They are kind of semi-independent structures, "dependent on the structure of being" but not bound by it. There is also a shift in his view in this area. In his early German writings the demonic is absolutely central to his thinking - later the concept of estrangement take over much of the role of the demonic.