Worry is the mind's way of trying to deal with a fear, to explain it, verbalize it, define it, and organize it, so the fear is not so shapeless and menacing.

Worry can be exhausting and destructive. But it can also be creative. Which one it will be depends on our attitude toward it and how we use it. In the same sense that fear is courage in the making, worry is wisdom in the making. It seems to threaten us, but it is also trying to help us.

Lewis Richmond in Work as a Spiritual Practice