Funny, I don't remember Van Helsing casting spells.
I've never read the other two books you mention. Does either one of them actually make use of divinely-granted magical powers? And if so, which ones?
Face in the Frost, yes. High Crusade, not as such. Like Stoker's Van Helsing, you have a man of science and of God who used his knowledge of Heaven and earth to achieve "magical" effects. It's an archetype that's quite common in the Verne/Burroughs style 19th-early 20th C. adventure story.
And that's where the disconnect between the original cleric and what it's become in D&D over the years comes in. The cleric was originally a bureaucrat, scholar, functionary, or other office holder within a crypto-Catholic medieval society - literally a "cleric" by the dictionary definition of the word. Some of his "spells" were miracles associated with Bible stories and tales of the saints. Others of his "spells" were applications of his superior knowledge of the nature of the world (which would include the nature of God). The 1e PHB models this by mading the distinction between early level spells, which the cleric could produce on his own, versus later level spells that he needed to beseech from his deity.
A great example of the kind of lower-level clerical "magic" is the Zelikman character in Michael Chambon's
Gentlemen of the Road. Also, I think Indiana Jones would be a good example of a secular modern take on a cleric - university professor who uses his knowledge of this and the spiritual world to find treasures.
However, since its inception, the cleric has morphed into this weird pagan warrior-priest identity that shares with the druid a strange mid-point between a paladin and a wizard. I think three big things contributed to create the change in the cleric.
First, as OD&D morphed into 1e, TSR's official take on D&D's cosmology changed from an implicit Christianity to an explicit mixed-up polytheism. So the tie between the medieval Catholic clergy and the cleric was severed really early, leaving us with Christian artifacts (the prohibition on edged weapons, for example) that didn't make much sense in the new paradigm. (Why wouldn't a priest of Odin, for example, use spears? A priestess of Artemis use a bow? Etc.)
Second, the 19th C. notion of the natural connection between God and science, that it was the duty of those who studied one to study the other, is almost completely alien to us in the 21st C.
Third, as the game began to focus more on the role of classes in combat, there was an increased role in figuring out exactly what a cleric was supposed to be doing in combat. Originally he was just a normal guy who could be as tough or wimpy as anyone else, but wasn't trained in martial weapons. Maybe he was a tough "Father Flanagan" type who preached with his fists as well as he did with his Bible, or maybe his was a wimpy scholarly type. His class didn't really tell you. Anyone objecting to Indiana Jones as a cleric because he uses a whip is thinking of latter day D&D clerics - in OD&D, what he does in combat, if anything, doesn't tell you whether he's a cleric or not.