Until I began this series I'd never noticed how present and numerous fences are in our lives. They're everywhere– either to keep something in, or keep something out. Fences remind me of the other kinds of barriers we build around ourselves and our lives.

Some fences are fiercely forbidding: steel chain-link or sheets of gray corrugated tin, topped with barbed wire and coils of knives and patrolled by nervous attack dogs. Their message is perfectly clear: Keep Out.

But some fences are beautiful weathered-wood or stone, settled into a living landscape, aging gracefully and full of character. They have history. They have stories to tell.

The farther you go out from the cities, the simpler the fences become. Made of sunbleached barn-wood scraps, leaning, swaying, falling down. And commonest of all, simple posts and wire, set there to keep the livestock from wandering, but other creatures including human beings can pass through, under, or over them with ease.

Farthest out, where only the highways and the trains go, the fences become barely visible, faint dotted lines across the vast sweep of the landscape, fading into grassy plains, mountains and sky. These may be the most beautiful ones, because they remind us how impossible it is to fence in anything that belongs to God, and after all, it all does.