I remember reading somewhere that Russell's "Why I Am Not A Christian" was partly a response to C.S. Lewis' twaddle. Specifically "Mere Christianity."
When I was trying to figure out what I believed (or not), umpteen Xians urged me to read "Mere Christianity." They claimed that Lewis answers all the Big Questions, and that "MC" would convince me Xianity is absolutely true, using logic and rationality alone. Nearly everybody claimed it was the best argument for Xianity ever.
Well, if you've read that over-rated POS, you know it does no such thing. I remember putting it down and thinking something like: "Jebus on a trailer hitch! THIS is the absolute best argument for Xianity? Then Xianity is really in deep shit."
Here's somebody who agrees with me, Jeffrey Shallit, so naturally I'll link to him. I really like his conclusion:
Let's ignore all the hidden assumptions here and accept Lewis's analogy: theology is like a map. Well, then it is a very poor map indeed. If you compare two contemporary maps of the same place, you usually find lots of commonalities between them.
Not so with theology -- even if you restrict yourself to Christian theology. Christians can't even agree if faith alone, or good works plus faith, are required for salvation! Remember that itsy-bitsy schism called the Reformation? Why wasn't Lewis a follower of Joseph Smith or Mary Baker Eddy or Ellen G. White? They had their own competing maps, after all.
Maps are supposed to render what is there, not what one imagines is there. It would be a poor map indeed if one went to visit the place mapped and found it did not exist. But this happens all the time with theology; even Mother Theresa strongly doubted her own theological map. But why? Wasn't it based on, as Lewis claims, "the experience of hundreds of people who really were in touch with God"?
If theology really is a map, then it's more like a malfunctioning GPS. It's the kind of map that, if you follow it, takes you off the road and into the water. A really bad theology will fly your jet into buildings. Sometimes you'd be lucky just to survive.
http://recursed.blogspot.com/2014/06/the-vastly-overrated-c-s-lewis-shallow.html