Firstly, I'm not English, I'm Welsh. Both part of the UK, but decidedly different attitudes to certain things, which may or may not be relevant here. The people in the Welsh valleys have a tradition of being very regular church-goers, but I don't know if that still applies to the more recent generations.
I know (knew? It's been three years this weekend since I left the UK) plenty of people who go to church, but I didn't know anyone under 40 who did. Whether that's representative of a national trend, I couldn't say. Plus, maybe it's just a case of 'birds of a feather' and I didn't know people who went
because I didn't go. After all, I knew a lot of people who were into nightclubbing, but if I hadn't been one I probably would have known a lot fewer.
There's also the fact that someone may well believe in God, just not go to church. Impossible to tell how many people I knew who fell into that category.
A week from this Thursday, I'm getting married

, here in Canada. Our ceremony is deliberately non-religious as neither myself nor my fiancee are into it. A few of her friends are, however, so I've been warned to be on my best behaviour if anyone asks why we don't have any of that 'In the sight of God' stuff (I tend to get a bit wound up when anyone expects me to fall into line on that sort of thing and some - not all - of them get a bit insistent). 'Young' people going to church
seems to be more prominent here in Ontario than it was back home.
As far as other countries are concerned, I honestly don't know. Some - Italy, Spain, Ireland - appear to have large church-going populations (based on what I've read and observed while travelling), but I've never seen any official statistics.