To be post-Christian has meant different things at different times. In 1886, The Atlantic Monthly described George Eliot as "post-Christian," using the term as a synonym for atheist or agnostic. The broader—and, for our purposes, most relevant—definition is that "post-Christian" characterizes a period of time that follows the decline of the importance of Christianity in a region or society. This use of the phrase first appeared in the 1929 book "America Set Free" by the German philosopher Hermann Keyserling.
The term was popularized during what scholars call the "death of God" movement of the mid-1960s—a movement that is, in its way, still in motion. Drawing from Nietzsche's 19th-century declaration that "God is dead," a group of Protestant theologians held that, essentially, Christianity would have to survive without an orthodox understanding of God. Tom Altizer, a religion professor at Emory University, was a key member of the Godless Christianity movement, and he traces its intellectual roots first to Kierkegaard and then to Nietzsche. For Altizer, a post-Christian era is one in which "both Christianity and religion itself are unshackled from their previous historical grounds." In 1992 the critic Harold Bloom published a book titled "The American Religion: The Emergence of the Post-Christian Nation." In it he cites William James's definition of religion in "The Varieties of Religious Experience": "Religion … shall mean for us the feelings, acts, and experiences of individual men in their solitude, so far as they apprehend themselves to stand in relation to whatever they consider the divine."
