The Law of Undulation

On the drive to Cincinnati yesterday, I listened to a radio dramatization of "The Screwtape Letters," C.S. Lewis' famous  look into the mentoring relationship between two devils – a junior tempter (Wormwood), and his uncle, a senior tempter (Screwtape). In the story, Wormwood is tempting his first human, and his uncle gives him tips and hints about how to adequately keep humans away from the "great enemy:" God.

I made it through about half of the set yesterday, and was pleasantly surprised at the quality of the dramatization. I was totally engrossed. The voice acting helped, too – Andy Serkis (Gollum) was fantastic as Screwtape, and the other actors, though lesser known, performed their parts equally well.
I was struck yesterday by the dramatization of the eighth letter from Screwtape to Wormwood, dealing with the "law of undulation." I'd quote the whole chapter if I could, but that wouldn't be exactly legal – so, just a snippet. (Someone has posted the whole chapter, and most of the book, here).

Humans are amphibians—half spirit and half animal. (The Enemy's determination to produce such a revolting hybrid was one of the things that determined Our Father to withdraw his support from Him.) As spirits they belong to the eternal world, but as animals they inhabit time. This means that while their spirit can be directed to an eternal object, their bodies, passions, and imaginations are in continual change, for to be in time means to change. Their nearest approach to constancy, therefore, is undulation—the repeated return to a level from which they repeatedly fall back, a series of troughs and peaks. If you had watched your patient carefully you would have seen this undulation in every department of his life—his interest in his work, his affection for his friends, his physical appetites, all go up and down. As long as he lives on earth periods of emotional and bodily richness and liveliness will alternate with periods of numbness and poverty. The dryness and dullness through which your patient is now going are not, as you fondly suppose, your workmanship; they are merely a natural phenomenon which will do us no good unless you make a good use of it.
To decide what the best use of it is, you must ask what use the Enemy wants to make of it, and then do the opposite. Now it may surprise you to learn that in His efforts to get permanent possession of a soul, He relies on the troughs even more than on the peaks; some of His special favourites have gone through longer and deeper troughs than anyone else. The reason is this. To us a human is primarily good; our aim is the absorption of its will into ours, the increase of our own area of selfhood at its expense. But the obedience which the Enemy demands of men is quite a different thing. One must face the fact that all the talk about His love for men, and His service being perfect freedom, is not (as one would gladly believe) mere propaganda, but an appalling truth.

Lewis goes on to discuss the role of free will in the "war" for human souls, but that's a slightly different topic (and, of course, a very debatable one). The "Law of Undulation" is, in itself, a broad topic that we can apply to our lives and walks of faith in a variety of different ways. With this blog post, I mostly just wanted to point out how much I believe in the point that Lewis is making – that our lives naturally have highs and lows, because of the way we have been created and because of the sinful and broken nature of our world. Often, when we're in a valley, we look only for the path that will take us to the next peak – but we should recognize that God is in the valleys as much as or more than he is in the peaks. When we find ourselves in a downward trough of undulation, we should ask ourselves what God wants to make of it.

This pattern of undulation won't end until we're at home in heaven. There's a verse in Isaiah that speaks to this:

Every valley shall be lifted up,
and every mountain and hill be made low;
the uneven ground shall become level,
and the rough places a plain.
And the glory of the Lord shall be revealed,
and all flesh shall see it together,
for the mouth of the Lord has spoken.”
- Isaiah 40:4-5