Lilith

Lilith, written by the father of fantasy literature, George MacDonald, was first published in 1895. Its importance was recognized in its later revival in paperback by Ballantine Books as the fifth volume of the celebrated Ballantine Adult Fantasy series in September, 1969.

Lilith is considered among the darkest of MacDonald's works, and among the most profound. It is a story concerning the nature of life, death and salvation. Many believe MacDonald is arguing for Christian universalism, or the idea that all will eventually be saved. (Summary from Wikipedia)