The natural restorative faculties are double-edged swords.  Although their natural tendency is to fight illness and infection, they can also bring about new harm.  Excessive fever and inflammation may cause organ damage and death.

I have been speaking of the restorative faculties of the body, but the soul also has restorative faculties, and these too can cut both ways.  For example, a boy deprived of his father will seek other opportunities for male bonding, which is healthy and good; but he may have an excessive craving for the approval of other males, which may do him further harm.

Insofar as it is purely natural, even the longing for God has this double-edged quality.  There are plenty of evil religions.  In a phrase of unforgettable poignancy, C.S. Lewis once described pagan mythology as “gleams of celestial strength and beauty falling on a jungle of filth and imbecility.”  Our nature can be fully and perfectly healed only by that which is greater than our nature.

The Lewis quotation is from Perelandra, Chapter 16