I'm new to the website, so to avoid posting where I shouldn't be posting, I just wanted to recommend a very, very good CHRISTIAN book titled:
The Bondage Breaker
by Neil T. Anderson
published year 2000
Its written for Christians who are somewhat more mature than newly converted Christians.
It describes, and provides full scriptural reference and support, the activity of demonic influence in our lives and how despite our faith that demons actually do seek to find cracks in our armor to penetrate and harm us. Includes case studies / personal letters from people he has helped.
The author has been writing since the late 1960's and has been a pastor and Christian Counselor as well as Bible College Professor. He knows his stuff and his faith is solid. REPEAT: His faith is absolutely solid & his well written text is a reference book I plan to purchase... as I'm using a friend's copy right now.