For seven days King David fasted. Day and night he went without food as he prayed desperately for the life of his newborn child. The baby had been born as a result of his affair with Bathsheba, an adulterous affair that had led to the murder of Bathsheba’s husband. From the moment the baby was born, it was evident the child’s life was hanging by a slim thread. So David prayed for the life of the child. He prayed with great intensity. He fasted as part of his prayers, hoping that by his petitions and by his avoidance of food he could make God be gracious to him and let the child live. But on the seventh day, in spite of the king’s hunger and all his prayers, the baby died.

Fasting, such as King David did, used to be a regular part of religion. People fasted as a sign of sorrow over their s…