I'm from Belgium, born in 1979, so I'll give you some insight since you're interested :).
My grandparents (farmers) went to church every Sunday. In those days it was kind of like a central meeting place to meet your neighbors. The Church back then also tried to push certain rules on people, that people for obvious reasons didn't like so much. I know my grandma never really believed in god, but my grandpa did.
My parents are like half-believers. I guess they believe in something, but that generation already knows Jesus didn't really walk on water etc. They might still believe in an afterlife. They had periods where we went to church every week, and other periods where we didn't go.
Then my generation: we were raised in school as rational people. And as you might know, rationality and religion never go well together. None of my male buddies believes in any religion. We might have a good laugh about it, and find the concept overall ludicrous and obviously false. It's 100% clear to us that it's all bullshit and make-believe.
For the women, they believe in "something", something "bigger than us". That's all I can say about it.
But overall, the Church has lost it's power due to lecturing people what they should and shouldn't do, and also obvious false claims, misconduct, etc. Nobody likes the one who claims to know better than the rest.
My wife is from Slovakia, and I would say they are running about 1 generation behind concerning religion. Churches there are now getting less and less people, while in Belgium that already happened a generation ago.
We still have certain regions that are more religious than others. And I know in the Netherlands there is a 'bible belt' where people are extremely religious, not taking anti-conception and all those other rules (they end up having 12 kids).
If you teach people rationality and learning to be sceptic, it's hard to sell them on something where you can live forever, as long as you follow some rules made up 2000 years ago.