What are the motifs in Mark Twain's Letters from Hawaii by Mark Twain?

Despite his own Christian faith, Mark Twain's attitude toward religion is a complicated one. On the one hand, Twain concedes that American missionaries have brought civilization to the "savages" of Hawaii, transforming them from human-sacrificing pagans into honest, hard-working church-goers. He also notes, however, that missionaries tend to be hard, self-righteous and unforgiving, characteristics that don't mesh with Twain's own understanding Christian ideals.