That narrows it down. Do you realize that an atheist who believes in demon possession is by definition not an atheist? It’s like claiming one is a vegetarian meat-eater.
If you don’t think BioLogos supports demon possession check out this thread from 2016
My own position is that angels and demons do exist, but there is no such thing as demon possession. The ancients attributed things like mental illness and epilepsy to demon possession because they didn’t know any better. But Jesus really did heal these people from what they were actually suffering from.
Simply believing in demon possession, witchcraft, and the like can cause terrible suffering. Just watch this very short video Report Decries Treatment of Mentally Ill in Ghana and see the terrible things people endure when there is inadequate care for the mentally ill. It’s just heartbreaking-- mentally ill folks are actually chained up in prayer camps!