The average American can’t answer basic questions about world religion, according to a recent Pew Research Center survey, which prompted renewed calls for religious study in public schools. In many states, however, that education already exists. The overall numbers are still small, with about 10 percent of schools featuring academic courses in religion, usually focused on the Bible. But the last five years have seen the first major expansion in decades. More than 40 states have districts that teach academic Bible study; five of them have passed laws to encourage it, offering, in some cases, curricula guidelines or public funds.