Controversy over the First Amendment’s guarantee of freedom of religion is as old as the Bill of Rights itself, but as law professor Stephen M. Feldman notes in his introduction to Law & Religion: A Critical Anthology, “The relationship between law and religion in America has become increasingly controversial since World War II.” Feldman explains that the increased controversy is due in part to the increasing number of freedom of religion cases on which the Supreme Court has ruled since the end of the war. Before the 1940s, he points out, the Court did not even recognize that the First Amendment’s establishment clause—“Congress shall make no law respecting an establishment of religion”—or the free exercise clause—“or prohibiting the free exercise thereof”— applied...