As a college student, I participated in the American Studies Program in Washington, D.C. A professor said something that changed my life: "God has not just called you to himself through salvation in Christ. He has also called you to a specific role in his kingdom, and only when you discover what the Puritans called the "particular call" will you experience true meaning, purpose, and satisfaction in the Christian life."

I'd never heard that before. Newly zealous for God, I desperately wanted my life to count. A political studies major with a business minor, I was struggling to understand why God would care about politics or business. I debated whether to switch my major to something more "spiritual" like biblical studies.

Wanting to know more about "particular calling," I asked my professor to suggest a book on calling. He could not think of even one. I decided to do my own research. What I discovered baffled me. The doctrine of calling is one of the most significant teachings the Puritans ...