Gordon MacDonald writes in "Cut and Sharpen”:

Once, when my wife, Gail, and I were hiking the high meadows of the Swiss Alps, we saw two farmers cutting the high-standing mountain grasses with scythes, a hand-mowing tool that has been around since ancient times.

Drawing closer, we noticed that both paused periodically and produced from their pockets something resembling a flat stone. Then in the same graceful manner, they drew the stones back and forth across the scythes' blades. The purpose? To restore sharpness.

The sharpening done, each returned to the cutting.

We observed them repeat this process—cut and sharpen, cut and sharpen—several times: ten minutes (give or take) of cutting followed by five minutes of sharpening.

[But] why waste five minutes sharpening the blades? We're talking here about 20 minutes of unproductive time each hour. Why not keep cutting, get the job finished, and head home at an earlier hour? Because with every swing of the scythe, the blade becomes duller. And with the increasing dullness, the work becomes harder and less productive. Result: you actually head home much later. Cutting and sharpening are both part of a farmer's work.

In my [younger] years, I didn't appreciate this cutting/sharpening principle. I'm embarrassed to admit that I usually gave attention to the sharpening (or the spiritual) dimension of my life only when I needed something beyond my natural reach or when I found myself knee-deep in trouble.

The cumulative results of a life lived like this became alarming. It led to dullness of the soul.

While talking a lot about God, I had very little practice in listening to him …. I tended to become bogged down in matters of secondary importance, neglecting truly important things.

I often complained of fatigue: not only physical fatigue, but spiritual and emotional emptiness. Sometimes I became flooded with temptations to envy, impatience, ambition, discontent, wandering thoughts.