In the mid-1960s, two people participated in research on the effects of darkness on the human psyche. They entered separate caves, while researchers tracked their eating and sleeping habits. One remained in total darkness for 88 days, the other 126 days. Each guessed how long they could remain in darkness and were off by months. One took what he thought was a short nap only to discover he’d slept for 30 hours. Darkness is disorienting.

The people of God found themselves in the darkness of impending exile. They waited, unsure of what would take place. The prophet Isaiah used darkness as a…