A.W. Tozer emphasizes the importance of variety in spiritual practices to avoid monotony, suggesting that even the most devoted souls can become stagnant if they do not occasionally shift their focus. He references Von Hugel's idea of 'neutral cost' in prayer, advocating for breaks from spiritual exercises to engage in simple, earthly activities like walking or gardening. Tozer illustrates this with the Israelites' journey in the wilderness, highlighting that constant movement was essential for their growth. He notes that great Christians evolved over time, requiring different spiritual exercises at various stages of their lives to maintain their spiritual vitality.

Some of the purest souls have written of the dangers of continuous spiritual exercises uninterrupted by lowlier considerations. Von Hugel speaks of the ?neutral cost? of prayer and advises that we should sometimes break off thoughts of heavenly things and go for a walk or dig in the garden. We have all known the disappointment felt when returning to a passage of Scripture that had been so fresh and fragrant the day before only to find the sweetness gone out of it. It is the Spirit?s way of urging us on to new vistas. I notice that in the wilderness God kept Israel moving. One may wonder what would have happened if they had camped in one place for forty years. The lives of the great Christians show that they differed not only from each other but from themselves at different periods of their lives. Spiritual exercises that helped them at one stage of their development later became useless and had to be changed for others.