Just because his book was reviewed by a Fabian socialist doesn't mean anything. That Hideous Strength is a cool book. It reminds me of "Halloween III: Season of the Witch," a movie that shows how technology is pagan, Celtic magic on a grand scale.
Just remember that "pagan" or "Celtic" is a euphemism for "Jєωιѕн." But Jews are pagan now, and have been ever since they rejected Christ. The idea that they have a "religion" is hogwash. They are abandoned to sin and fleshly pleasure and money.
If you want to question C.S. Lewis' Catholicism -- and this is very easy to do -- check out another book in the "Space Trilogy" called Perelandra, I believe. It's some bizarre, baroque fantasy about a man stranded on a planet where there are only two life-forms, himself and some alien chick who turns into a surfboard and takes him riding up and down on big purple waves ( or something like that, I don't remember all the details ). It's like a porny sci-fi Adam and Eve fantasy. Really lame.