Letters from the Earth is a bit of a strange animal to begin with. The bulk of it is made up of stories centered around antediluvian Biblical passages and characters, while the rest is a hodge-podge of previously published, unpublished, and unfinished essays and story sketches. The title story consists of letters written by Satan to the other archangels as he spends time in exile on Earth. The framing device is problematic since the "God" and "Satan" of Twain's story are wholly separate characters from those in the Bible. Twain seems to have sought this angle to heap harsh satire upon Christians' extrapolation of God's character as drawn from scripture. Twain does get pretty damn harsh about the biblical God and his followers, and it's understandable why his daughter delayed this book's publishing out of fear for her father's reputation.
For my part, I love Twain's satire and essays in general, and I felt the jokes, though spiky, land with a fair amount of truth in this book. Megan disagrees, finding Twain's tone to be self-important and his style wordy. (You'll have to judge for yourself based on the snippets I pulled for the following section.) Though these bits were unpolished and many unfinished, I felt like I was getting to see Twain knit his classic zingers. Letters from the Earth testifies to Twain's amazing creativity, and for those who are already die-hard fans of his satire, this book will reward their curiosity about what else Twain had cooking in his brain.
Leading up to the story of Noah: "By help of those visiting foreigners the population grew and grew until it numbered several millions. But it was a disappointment to the Deity. He was dissatisfied with its morals; which in some respects were not any better than his own."
Satan on the invention of hell: "...as the meek and gentle savior [Jesus] was a thousand billion times crueler than ever he was in the Old Testament."
From Methuselah's diary: "[The Jabalites] worship no god; and if we in goodness of heart do send a missionary to show them the way of life, they listen with respect to all he hath to say, and then they eat him. This doth tend to hinder the spread of light."
Twain on the idea of repentance: "[People who do not repent their good deeds] ought to be in heaven; they are in the way here."
From "The Damned Human Race": "An oyster has hardly any more reasoning power than a scientist has; and so it is reasonably certain that this one jumped to the conclusion that the nineteen million years was a preparation for him; but that would be just like an oyster, which is the most conceited animal there is, except man."