Apparently there are several scientific studies that indicate, like universal facial recognition of emotions in comic books is cross-cultural and genetically wired, a universal genetic need seems to exist for certain story lines. We simply crave these stories told over and over again in countless re-envisioning. There is a reason that the bible, Gilgamesh,and Baelwolf, Homer story lines continue to be re-invented.
I would suggest that there isn't a published book that doesn't have jewish or christian roots that one could trace back to those works and some of those stolen from earlier myths (flood and creation stories). Star Wars, Star Trek, Heinlein, Gone with the Wind, Harry Potter, Dresden books, etc. all uphold biblical storyline concepts such as good over evil, David vs Goliath, David and Bathseba's adultery, even the sensual x-rated sex poetry in the Book called Songs of Soloman. (And how many of your reached for a bible to check out Soloman?) Let's face it--those ancient stories survived as long as they did, because they speak to us deep inside--are even genetically wired to do so.
That being said, the fact that you defined your work as 'christian' might be troubling. Reuse of biblical story lines is par for the course, but your acknowledgment of your faith rewakening might indicate an unconscious leaning that is on the 'heavy' side. Still, this is your work! The Muse of Faith can be a wonderful guide and ignoring her could block a faith journey that you need to take for yourself. Writing for publication is highly unlikely anyway. Have the courage to write where you are led. If a higher power is working through your fingertips, s/he is also working through your mind and perhaps healing or opening new doors to your faith journey. Also, it never hurts to think a divine hand is guiding your hand--cause you might complete the work! "God" can be a powerful reason to not procrastinate getting those words on a page! *cue lightning* *smiling*
Happy travels as you explore with your Muse of Faith.
Edited because I never answered your question... I never enjoyed the Narnia series, but I loved and adored his adult space trilogy of Out of the Silent Planet, Perelandra, and That Hideous Strength. I haven't revisited them in years, but you might find them helpful. I read them as a teenager and the symbolism went right over the top of my head--which is where a 'christian' philosophy works best in my humble opinion.