Broadly speaking, the UK is a Christian country in a cultural sense. I think the confusion sets in because the British who identify as Christian are also broadly impious in relation to their more devoted American counterparts.
Even amongst Brits who would willingly tick "Church of England" on a census form, it seems to be only a minority who attend church, perform religious rituals, proselytize, or attempt to defend their faith.
I caught my wife ready to tick CofE on a form once and asked her if she believed in God. She thought and said "Well, no. Not really." Yet, culturally, she was brought up to just say she was CofE and a Christian because, culturally, she lived that way without ever being pious or knowledgable about the theology of it.
Even amongst Brits who would willingly tick "Church of England" on a census form, it seems to be only a minority who attend church, perform religious rituals, proselytize, or attempt to defend their faith.
I caught my wife ready to tick CofE on a form once and asked her if she believed in God. She thought and said "Well, no. Not really." Yet, culturally, she was brought up to just say she was CofE and a Christian because, culturally, she lived that way without ever being pious or knowledgable about the theology of it.