I have to say that when I first read TLTW&TW, aside from when Aslan submitted to sacrifice by the White Witch the religious themes went right over my head and I was much more focussed on the centaurs and fauns and the talking animals so I just enjoyed the story for itself.
TLTW&TW wasn't my favourite story and Lucy certainly wasn't my hero - I preferred Edmund and as it went on the later books were much more to my taste as the animals and more 'indigenous' characters became more prominent and the classical creatures took a back seat more. Although Greek Myth was my 1st love in fantasy I really didn't like it mixed in with the rest and my actual favourite character was Puddleglum (Silver Chair) and then Reepicheep (Prince Caspian & Voyage of the Dawn Treader) but overall the final book, The Last Battle was at the top of the list of my fave books (until I read Tolkien
That book I did get was religious - I was older for 1 thing, but what appealed in that was the message that if you live a good life then you get your reward eventually, regardless of which faith you follow
- the bit where the true believer in the 'evil' god Tash was also admitted to paradise with Jill & Eustace etc. In a school run by nuns this was something novel in that we just didn't know anything at all about other religions which included CofE and non-conformist churches. They weren't 'proper' christians apparently
Looking back this was highly influential in how I came to reject catholicism because of their narrow interpretation of what's 'right' and the 'us' and 'them' attitudes too. In some respects as an adult I don't much like Lewis' own robust brand of christianity which, when I do look back on his work comes across as self-righteous in the extreme, and the books themselves are pretty crude at times but the basic message of decency and not being afraid to 'do good' isn't one to be sneezed at, but sadly, the books are not really time-proof in the way Tolkien's work was. The reason for that is one that Tolkien himself put to Lewis - you should make your world unique and consistent and I'm afraid, charming as talking animals are, mixing your mythologies really don't work past the age of say 10. But then children these days aren't quite so naive as we were back in the 60's...