Okay I'll admit it. I'd really like to be able to churn out a nice, lengthy, review after every book I read (much like Mr. Challies), but I very rarely take notes when reading on my free time and I'm, well, not exactly in the "school/educational" mode at the moment. Thus, I'll have to make due with a "reaction post."
Overall, I found C.S. Lewis' The Screwtape Letters to be a very good, thought provoking, and interesting read. I'd recommend it to almost any semi-mature Christian. There are two main things to observe before I launch into the bulk of the review, and it is important to keep these things in mind. First, this is a fictional, theoretical, speculative, and very personal book. It would be a grave mistake to assume that everything Lewis wrote is founded on Scripture, and I'm sure he would say the same. This is just one guy's take on spiritual beings, I personally doubt that Hell and devils really function the way Lewis describes them. Second, Lewis notes in the introduction that not everything Screwtape (the first person narrator of the book, a "high-ranking" devil) says is true; rather, it is only what he thinks is true.
That said, there are many things in the Screwtape Letters that one can learn and meditate upon. Namely, the nature, processes, and forms of temptation and sin. There were many great lines (probably one every other chapter) that I wish I could quote here. In other words, I was frequently examining my own life while reading this book, and I found several of Screwtape's examples and advice to be all too familiar. Several good points include:
--The spirit world is very real. Satan and his devils are constantly working to draw people away from God via lies, temptation, and confusion. They are always working to create the next huge damning worldview (in the specific case of this book: Nazism).
--The fact that every extreme a person could go to (except extreme devotion and service to God) can become dangerous and ultimately sinful.
--Pleasure is not in and of itself a bad thing; after all, God created pleasure. It should be noted, however, that the demons are quick to exploit and pervert this pleasure into sinful forms.
--A clear thinking head is Godly. One thing I found very interesting is that Screwtape often advocated confusion and unreasonable thinking. Lewis always painted reasonable and logical thinking as something that leads men to God. More often than not (actually, all of the time) devils try to confuse people, deaden their reasoning, and draw their mind away from the matter at hand. It is very interesting to consider that Screwtape takes satisfaction in the fact that "great scholars are now as little nourished by the past as the most ignorant mechanic who holds that 'history is bunk.'" All sin is ultimately foolish and unreasonable; it never makes real sense to do it, yet we too often are blinded to the simple truth.
Naturally, there are some things in The Screwtape Letters that I had to just flat-out reject. Most significant among this is the blatant Arminianism. This could, of course, be one of those things that Screwtape only thinks is true, because a God that "can only woo" makes for a much easier opponent for devils. Nevertheless, the whole "free will" thing was so prevalent in the book that I felt several points were worth addressing.
--God does not convince men to become Christians. Contrary to what Screwtape says (which Lewis may have considered untrue) God does have the power to directly save a person if He wants. He is the one that initiates, executes, and finishes salvation. Every stage of the salvation process directly involves the sovereign work of God.
--There is not some kind of "spiritual balance" between good and evil in the world. For some reason (probably due to Screwtape's perspective) this book left me with the impression that there is a delicate balance between good and evil, like two sides playing a game of strategy and constantly trying to exploit the other's moves. Yes, there is a struggle between good and evil, but God is not trying his best or failing to completely overcome evil. Instead, He is tolerates it for a time yet will ultimately triumph over Satan and accomplish His will for the universe.
--I have very little authority to speak on this matter, but I'm fairly sure that Screwtape misses the exact nature of prayer as well. Through some confusing chain of reasoning, he manages to argue against the notion that God works out our prayers in accordance with His will. In other words, Screwtape thinks that our prayers were not "predestined" to occur because if they were, then we wouldn't pray freely. Rather, God does not foresee, but sees things in "His unbounded Now." I, quite frankly, believe that prayers are predestined and that they are more for our benefit and God's glory than anything else. God knows our thoughts and our heart, and I don't believe that our prayers convince Him to do anything. That's why we pray for many things, but above all we pray that the Father's will be done.
Above all, though, The Screwtape Letters did bring up a very interesting "logical contradiction" of sorts. As mentioned, Lewis says that not everything Screwtape says is true, and I'll probably grant him that. One wouldn't expect the "Father of Lies" or his followers to speak the truth. However, I've also been told that Satan and co. know better theology than even the most brilliant and learned theologians ever to walk this earth. If this is so, though, then the devils must know even better than we as Christians do, that their struggling is vain because God is omnipotent and will ultimately triumph in the end. Now I'm sure their hatred of God is so intense that they will continue to rebel until God casts them all into the lake of fire. Here's the thing about The Screwtape Letters though: Screwtape seems confident that his side will eventually triumph. Now given the Arminian (perhaps even Pelagian) view from which he operates, I can see this being a bit more plausible, as there really is a true, undecided battle for souls.
I'll leave you with that thought...and the recommendation that you read this book.