Yes, I remember reading C.S. Lewis'
Perelandra trilogy way back in my teens, around the time I also was introduced to Lewis'
Screwtape Letters (which, if you are not familiar with it, is a novel that posits a lesser demon (Screwtape) writing "progress reports" to his supervisor devil. Very Christian storyline, and funny in a sort of sad way when looked at now, but worth a read.
I quite enjoyed the first 2 books of the
Perelandra trilogy, but still remember the last book quite falling flat, when it stopped storytelling and became expository religiousity. Avoid that trap, and you'll likely have an interesting book. As a completely irrelevant aside, I remember reading (can't quote the source anymore) that Tolkien and Lewis were very good friends, and the character of Merlin that appears in
That Hideous Strength is an homage to the Middle Earth series, in that Merlin is supposed to be the 5th wizard of Middle Earth, otherwise unnamed.
As far as Dan Brown's "work" in my opinion, while it was a rousing action-packed ramble, it was full of grammatical and even some spelling errors, to say nothing of errors of logic and fact. It was a phemonenon that didn't deserve the hype it got, in fact, would likely have remained in well-deserved obscurity except for the hype. (not to be judgemental or anything

)