Letters from the earth is one of Mark Twain's posthumously published works. The essays were written during a difficult time In Twain's life; he was deep in debt and had lost his wife and one of his daughters. The book co...Letters from the earth is one of Mark Twain's posthumously published works. The essays were written during a difficult time In Twain's life; he was deep in debt and had lost his wife and one of his daughters. The book consists of a series of short stories, many of which deal with god and christianity.