A Sound Heart: The Life of the Flesh and Spirit

A sound heart—one that gives its supreme affection to the supremely good—is the very condition of physical health, "the life of the flesh" (Proverbs 13:30). Exell observes that science itself demonstrates this principle: the passions of grief, disappointment, anger, jealousy, and revenge derange the bodily system in proportion to their strength, while pleasurable emotions rooted in moral virtue give buoyancy and vigor to the body.

This truth carries profound implications for the church and the physician alike. First, bodily health—where the body's organization is normally sound—remains largely in our own hands. Heaven has given us both means and motives to cultivate happy conditions of heart. Second, Christianity proves indispensable in removing man's physical diseases, for moral evil stands as the source of all physical evil. Third, medical science remains ineffective until it practically concerns itself with the moral diseases of the mind.

The physician who ignores the connection between moral corruption and physical illness acts unscientifically. There exists no agent to remove moral evil but Christianity itself. As true morality advances in the world through the Gospel, so too advances the physical health of the world. The man most successful in promoting moral renovation of hearts through Christ becomes the greatest philanthropist, for he provides the drainage to carry away all the foul passions that poison the body.