I always pack a little book called The Case For Faith, by Lee Stroebel, when I set off on my travels. I have long been intrigued by the idea of “faith” and how fragile it sometimes can be. You understand, I’m sure.

In one section toward the end of the book, Stroebel interviews an elderly Canadian teacher, writer, and scholar named Lynn Anderson. This interview is one of Stroebel’s most important, because Mr. Anderson teaches him that doubt is not our biggest threat. The biggest threat, as you’ll see, is shocking. Read on.

I have found that when you choose the road of faith, you had better be prepared to detour down some dark side-roads – such as the cul-de-sac of Doubt, or the crooked highway of Disbelief. We cannot travel very far before we realize we are prone to wander off the main road far more than we would like.

In the interview, Stroebel is curious to find out if a man with the knowledge of Anderson had wrestled with the doubts himself. Mr. Anderson answers the question by considering the true nature of faith and doubt. To combat doubt, he says, we need to establish a clear object for our faith. What, exactly, is our faith based on? Is it founded on something very solid?

The theologian drew an illustration from his homeland to clarify. “We Canadians,” he said, “know there are two kinds of ice: thick and thin. You can have very little faith in thick ice and it will hold you up just fine,” he says, “and you can have enormous faith in thin ice and you can drown. It’s not the amount of faith you can muster that matters up front. It may be tiny, like a mustard seed. But your faith must be invested in something solid.

Interestingly, “Doubt,” it seems, is not the problem. The problem may be that we have too much faith. That’s right. We have a great deal of faith, but that faith is based on the wrong things. We can base our faith on human reasoning, current trends, eloquent sermons, long-held prejudices, or on the things that appeal the most to us.

We can have absolute faith in any of those things and go about our lives believing with all of our hearts that we are walking on ice as thick as building.

But thin ice will break, no matter how much you believe in it.