Having read the other posts in this thread I have to add my two cents worth.
Regarding C. S. Lewis' Narnia series I loved them has a kid and even at the age of 7 got the Christian symolism, (some of it anyway). What I didn't like was the kids we kids were supposed to identify with. I found them annoying and to use an expresion I was fond of at the time, "sucky". There were clearly an adults idea of "proper real" kids,from someone who had altered his memory about what kids were like and what they thought. I personally wanted them to "go away".
What loved in Narnia was the talking horses, Nymphs, Unicorns, Dwarfs, and of course my favorite Aslan the Lion. In fact the Christian symbolism helped me enjoy Sunday school more.
As for childhood being a magical time free from care, that wasn't true of me or anyone I know or of the vast majority of Children who have, will and do live. The idea of childhood being a sort of "shielded" "golden age" is an adult fantasy that has forgotten how childhood can be hell, (just like adulthood).
My opinion of C. S. Lewis' quasi-theological / philosophical efforts is not high. I simply can't take his question begging seriously.
Pierre