Stephen Prothero‘s new book is God Is Not One: The Eight Rival Religions that Run the World—And Why Their Differences Matter.
Thabiti Anyabwile reprints a helpful analogy from the book:
Which of the following—baseball, basketball, tennis, or golf—is best at scoring runs?
The answer of course is baseball, because runs is a term foreign to basketball, tennis, and golf alike. Different sports have different goals: basketball players shoot baskets; tennis players win points; golfers sink puts. So if you ask which sport is best at scoring runs, you have privileged baseball from the start. To criticize a basketball team for failing to score runs is not to besmirch them. It is simply to misunderstand the game of basketball.
So here is another problem with the pretend pluralism of the perennial philosophy sort: just as hitting home runs is the monopoly of one sport, salvation is the monopoly of one religion. If you see sin as the human predicament and salvation as the solution, then it makes sense to come to Christ. But that will not settle as much as you might think, because the real question is not which religion is best at carrying us into the end zone of salvation but which of the many religious goals on offer we should be seeking. Should we be trudging toward the end zone of salvation, or trying to reach the finish line of social harmony? Should our goal be reincarnation? Or escape from the vicious cycle of life, death, and rebirth? (p. 22)
Trevin Wax has a thoughtful review of the book—pros and cons—here.