Reddit reviews The Demonologist: The Extraordinary Career of Ed and Lorraine Warren

Well, An Exorcist Tells His Story, Hostage to the Devil, The Demonologist, parts of the Bible (KJV and NIV for comparison). It's difficult to find much good information on the Internet that isn't awash in silly spiritism or confrontational Christianity.

In the Catholic Church and most non-evangelical denominations, the person who is believed to be possessed is examined thoroughly by medical and psychiatric professionals. Sometimes these professionals are religious, sometimes they're not. When this person is cleared by the pros but the problems persist, the local bishop will authorize an exorcism.

People who are possessed (or oppressed or obsessed) range the full spectrum from complete atheism to devout faith. Their behavior can change violently if a holy item is brought near to them, even if they can't see it and have no reason to expect its presence.

The only way to explain all of this "rationally" is to decide that all of these books are complete fiction, that all the authors are liars, and that none of it ever happened, or didn't happen the way that they depicted it. You have to toss out everything.

In fact, you have to accept a conspiracy of lies, because these stories are everywhere and crop up constantly. You have to assume that all of the people who have come forward on these TV specials are crazy, horribly mistaken, or desperate for notoriety. All of them. That is not a statistically likely outcome at this point, given the sheer amount of data.

And neither is it an obscure process of nature which is just poorly misunderstood. Obscure processes of nature don't lift a 400 pound refrigerator and fling it across the kitchen.

I know I'm probably going to get counter-arguments on this. I really urge those people to read one of these books before they do so. Because what you understand of this phenomenon through popular culture is about 90% wrong.

Here is the best place to start, imo.