Find helpful advice in CS Lewis’ “The Screwtape Letters”

In The Screwtape Letters, CS Lewis has his main character explaining how humans are “half spirit and half animal” (37). Our spirit ever yearns for God, but our bodies are in thrall to biorhythms that ebb and flow. So humans, and Christians, according to Lewis, spend their lives in a “series of troughs and peaks.” Instead of maintaining a constant level, our inspiration and Christian believing tend to “undulation—the repeated return to a level from which they repeatedly fall back” (37). …
Does this vacillation sound familiar to you? It does to me. In fact, I’ve written about it several times. That’s because, until we understand it, this rise and fall in our Christian experience can be truly demoralizing… It’s during these dry times that we come to realize that our relationship with Christ is really his relationship with us. It is not ours to push or to manipulate or to control. …The great comfort for me is that these “troughs” in our believing don’t leave us where they found us. At least that is my experience. We don’t just “repeatedly fall back” to the same low level, as Lewis’ words might imply. Rather, our Christ spirit is strengthened by our patience and our moments of yielding. And so, each undulation brings a new wave, pushing us a little further onto the shore of spiritual life. (Turning Aside to See, 2011 ©️)