There is nothing wrong with studying the views on demons found in the Apostolic Fathers. Nor is there anything wrong with hoping that the study of those later texts may shed some light on some New Testament texts. Such things often happen. But there is no guarantee that the views of the Apostolic Fathers (on demons or anything else) are a reliable guide to the views of any particular New Testament author. There is no guarantee that because Fathers X, Y, and Z (or some average of the belief of the Fathers) did not accept demons, that Mark did not accept demons. In the end, in the absence of any surviving documents from people who knew and conversed with Mark, all claims about what Mark believed must rest primarily on what Mark wrote. So hopefully, here, Jonathan Burke will interpret what Mark wrote. I thank Jordan for instigating this discussion.