Short Review: This is an update to CS Lewis' classic Screwtape Letters. Intended to be a captured propaganda/training manual for young demons instead of letters from an older demon to a younger. Screwtape Letters was the first Lewis book I remember reading on my own (probably around 12) and I have read it at least a couple times since (but not recently.) But this didn't feel quite as good. It is less subtle for one thing. Also while I think that Farley has a lot of the right ideas, I think his solutions are sometimes over the top. For instance, I agree that sometimes people's repeated confessions of the same sin only serve to focus the person on the sin and they never live in freedom from the sin. But that does not mean that confession is bad, it just means that there are bad ways to do confession.
I would give this a 3.5 if I could. There are some good ideas here, but it lacks some of Lewis' literary subtlety and sometimes goes a but too far trying to remind us that we are saved by Grace and not by our own works (which I theologically affirm.)
My full review is on my blog at http://bookwi.se/operation-screwtape/