Letters from Hell by Valdemar Adolph Thisted (1815 - 1887)

"Letters from Hell" is a didactic Christian fantasy novel, with a faint resemblance to C.S. Lewis' "The Screwtape Letters." Otto, the narrator, has died in the prime of life. Through letters, he relates the torments and regrets that are a consequence of the self-centered and dissipated life he led in the world. He also describes the fates of other lost souls who inhabit Hell. (In this work, Hell is not the place of eternal torment, but the "holding area" until the final judgment.)
There is also a preface written by George MacDonald. - Summary by TriciaG