As an active Protestant in my mid-twenties I began to feel that I might have a vocation to become a minister. The trouble was that while I had quite definite convictions about the things that most Christians have traditionally held in common—the sort of thing C.S. Lewis termed "mere Christianity."I had had some firsthand experience with several denominations (Presbyterian, Anglican, Lutheran, Methodist) and was far from certain as to which of them (if any) had an overall advantage over the others. So I began to think, study, search, and pray. Was there a true Church? If so, how was one...