Also, remember when Lewis wrote that. 1942 wasn't like today... Any materialist at the time who claimed he was courageous could easily be just responding to persecution, not claiming that that was his reason for being a materialist.
Your understanding of 1942 is amazingly flawed. No-one in the developed world was persecuted for being a materialist at that time, but plenty were for their religion. Moreover, the fashionable belief at the time was dialectical materialism, and part of the claim made for it, by dialectical materialists themselves, was that it was the philosophy of the future.
Well, my first thought was Bertrand Russell being fired from CUNY, which was around 1940, although that was mostly because of his beliefs about sex (which are still directly related to his disbelief in religion). Religion classes in public schools were legal until 1948, and compulsory school prayer was legal until 1963. "In God We Trust" was declared the national motto of the US in 1956.
Another month has passed and here is a new rationality quotes thread. The usual rules are: