This question is asked of me so often that I’ve decided to post an *unedited* excerpt from my forthcoming Demons book (due out sometime in 2019 — it’s in editorial now). Here’s a brief take on the issue; part of a larger discussion:

What is spiritual warfare-from Heiser DEMONS MS unedited

I can honestly say that this book (Demons: What the Bible Really Says About The Powers of Darkness) is unique. There’s nothing else like it. This is due to two related factors: (1) It’s based on peer-reviewed scholarship on OT, 2nd Temple, and NT research; and (2) it approaches the subject in light of the neglected (omitted?) reality that the Bible frames supernatural evil in light of three ancient supernatural rebellions (Gen 3, Gen 6, Gen 11/Deut 32:8-9). Approaching things this way (which has heretofore not been done all in one work) allows us to see that 2nd temple and NT “demonology” and “Satanology” are not aberrations with respect to OT data.