Human beings straddle visible and invisible realities—the natural and the supernatural. I thought about these two worlds when I went out in a boat to watch whales off the coast of New Zealand. A whale would rest on the surface for a while, then breathe deeply a few times, his exhalations creating a spectacular spout, before plunging a mile deep to feed on squid.

Despite having its own lively habitat of marine plants and sea creatures, the whale must surface for oxygen from time to time or it dies. Though it knows little about the world above, it needs vital contact with it to survive.

I sometimes feel like that whale, coming up for spiritual air at regular intervals to stay alive. But there is no neat division between the natural and the supernatural. The world we live in is not an either/or world. What I do as a Christian—praying, worshiping, demonstrating God’s love to the sick, needy, and imprisoned—is both supernatural and natural.