What manner of man is this, or what manner of creature is it in the semblance of a man? (3.23)
Jonathan might not know what, exactly, Dracula is, but it doesn't really matter. The fight against evil is on!
But my very feelings changed to repulsion and terror when I saw the whole man slowly emerge from the window, and begin to crawl down the castle wall over that dreadful abyss, face down, with his cloak spreading out around him like great wings. (3.22)
This is one of the first hints Jonathan has that the Count isn't quite… human.
At least God's mercy is better than that of these monsters, and the precipice is steep and high. At its foot a man may sleep—as a man. (4.70)
Here "God" is being directly contrasted with the monsters.
[…] the lately glassy sea was like a roaring and devouring monster. (7.3)
The journalist describing the great storm at Whitby doesn't realize that the sea is, in fact, being controlled by a vampire, but his simile is pretty accurate.
[…] masses of sea-fog came drifting inland—white, wet clouds, which swept by in ghostly fashion, so dank and cold that it needed but little effort of imagination to think that the spirits of those lost at sea were touching their living brethren with the clammy hands of death […] (7.3)
Even though he doesn't know that the storm is caused by a vampire, the journalist (and everyone else) seems to have sensed that there was something not quite right about the fog.
Lucy's eyes in form and colour; but Lucy's eyes unclean and full of hell-fire, instead of the pure, gentle orbs we knew. (16.19)
The thing that makes vampire-Lucy so hard to take is that she still looks like good, pure, sweet Lucy. Evil is super evil when it disguises itself as something good.
As he had placed the Wafer on Mina's forehead, it had seared it—had burned into the flesh as though it had been a piece of white-hot metal. (22.43)
Thus are we ministers of God's own wish: that the world, and men for whom His Son die, will not be given over to monsters, whose very existence would defame Him. He have allowed us to redeem one soul already, and we go out as the old knights of the Cross to redeem more. Like them we shall travel towards the sunrise; and like them, if we fall, we fall in good cause. (24.12)
Van Helsing imagines that their struggle against Dracula is analogous to the medieval Crusades.
Quincey P. Morris
"Now God be thanked that all has not been in vain! See! the snow is not more stainless than her forehead! The curse has passed away!" (27.62)
Quincey Morris's last words announce that the evil Dracula has been destroyed. Good has triumphed yet again!