...[A]re talking about Derek Prince [died in 2003] or are you
confusing him with Dr. Frederick Price [still alive]? We
read many of his books and he [Dr. Frederick Price] did in fact
claim Christians could be demonized.
Right, a Christian cannot be demon-possessed (1 Jn
4:4). If you're currently demon-possessed, then you were never a Christian. You
may have thought you were (Mt 7:22); but, you were not (1 Jn 2:19).