I don't believe Lewis took the test, but it's plainly obvious from his writings that he was one of us He has also indicated in his autobiography about having a lot of INTJ traits, including disinterest in small talk and preferring to be by himself.
I guess I don't understand how the words weak or succumb could have a positive connotation. If my interpretation is wrong, would you mind telling me what you did mean to imply by your statement, "I can understand why some "weak" types succumb but NT's especially INTJ's/INTP, surely not?"
Thanks And, I am from the USA, although I can tell you that the role of religion in US culture greatly depends on what type of community you live in and choose to associate yourself with. Serious Christians et al are in the minority here too, although you can find them if you look.
I'd love to visit the UK sometime. Have you always lived there?