At any given moment, tens of thousands of religions, branches, sects, and belief systems are competing in a “survival of the fittest” battle as ferocious as anything in nature. These belief systems are locked in an endless fight for dominance, and with each generation there are winners and losers: only the “fittest” survive. Just like biological life, ninety-nine percent of the world’s religions are extinct, but the ones that survived into the modern era are quite remarkable. These religions are the very strongest and best—the fittest.