Author Malcolm Gladwell may not be known for writing on religion. His New York Times best-selling books “The Tipping Point,” “Outliers,” “Blink” and “What the Dog Saw” deal with the unexpected twists in social science research. But his newest book, “David and Goliath: Underdogs, Misfits, and the Art of Battling Giants,” also includes underlying faith-related themes, and not just in…