Bram Stoker's moral of the story
After a thorough rereading of Bram Stoker's Lair of the White Worm, the first impression is strengthened: the writer had possibly prepared some chapters of the book, and drafted other parts, while developing different narrative hypotheses --- then, he decided to publish the text "as was" at that time, all incongruencies and 'bugs' notwithstanding, as if he was in a hurry for some reason.
Anyway, his overall worldview is quite clear, and perfectly matching the one in Dracula. In general, a struggle of Reason against Chaos and Fury. More in depth, a religious battle of Light against Darkness. More practically, the triumph of the Western pattern of civilization: see, in the final part of the novel, the "white worm" turning into a rich "white clay" mine. Economy conquers Myth.
As to the religious side, the good Power is a general God, identifying much more with Nature than with Christ. In fact, whereas the personages playing the role of Satan are obvious both in Dracula and in The White Worm, no specific person embodies the Savior, except maybe the main characters, but in a very pale way.
The most interesting "moral," however, in both novels, is that the villains are solitary, introvert, selfish guys; while the most positive values turn out to be solidarity, team job, sharing, cooperation. This is truly the Saving One.