Jovial were the celebrations of November 2013 on the fiftieth anniversary of C. S. Lewis’s passage into eternal glory. The panegyrics got me thinking about my own journeys through Lewis’s works, some repeated more times than I can count. It seemed like a good occasion to read the books I’d missed, reread the ones I loved, and figure out what it was that drew me—and countless others—so strongly to Lewis. Chief among the delights are his calm and accessible accounts of Christianity, his fair dealings with other religions, and the way his storyteller’s instincts bring the faith so vividly to life. At the same time, I hoped to sort out what in his thought has left me uneasy, uncertain, and unconvinced...