If it were that self-apparent, wouldn't we expect Kant, Kierkegaard, Anselm, Anscombe, Heidegger, Gödel, or the countless other philosophers and heavy thinkers of the past several centuries to have not even wrestled with the question?
Heck, even Antony Flew, a contemporary philosopher of religion who was a staunch advocate of atheism for much of his career, later declared himself a theist. Did he simply fail to realize that it's pretty obvious that religion is make-believe?
What do you know that they didn't? What did they know that you might not?
First, the "God of the gaps" has basically disappeared. All natural phenomena in our personal experience are understood well enough that we can say with confidence that nothing supernatural is required to explain them. That doesn't mean that every individual understands them well enough, and while it's not a hard binary distinction, there is certainly a correlation between spirituality / belief in the supernatural and lack of understanding of natural science.
Second, religion is to a large extent social glue. As humans increasingly live in large cities, social glue in general is disappearing, and religion is just one facet of that.
What came before the big bang? And why does it seem that all matter came from one location in space? Seems to break the second law of Thermodynamics even. We don't know. Will you put your faith in the idea that the system of science CAN EVEN know eventually?
Can set theory prove everything? We know that it cannot prove a number of things, thanks Turing. Those things end up being pretty important to proving everything evidently. Science rests on mathematics.
Why should you believe in a particular philosopher's revealed truth? Well it seems consistent with the rules of logic. Seeing as set theory is the most concrete, repeatable form of logic we've ever come up with, see the above for why thats maybe not the best stance to put your faith in.
Maybe believe in nothing? But you will believe in something, even by accident. The nature of human heart is to make idols.
All require leaps of faith at the bottom of them. Either in systems or individuals.
Philosophy - is backed by reasoned arguments and open to debate
Mathematics - is our construction, how can we not believe in our own invention
Religion - requires that you buy into an archaic fairy tale, with no empirical proof or reasoned argument, to the extent that you will sanction wars and oppressive gender inequality on the basis of unsubstantiated belief
...
One of these things is not like the others
What the evidence shows is that we are meat, with sentience being an illusion of complex chemical reactions. What “rights” does meat have? Why can’t we, for example, kill drug dealers, if that would make life on earth—the only kind of life there is—better for all the other meat sacks? The Chinese communists at least practiced atheism correctly and followed it to its logical conclusions.
I think a more accurate characterization would be that European Christianity has evolved into a different religion which retains the notion of the divinity of the individual, but drops explicit references to God.
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.
So all info basically came from what they knew from their parents, the farm, their neighbors, and on Sunday what the priest said. There were school teachers of course, which were regarded the same as a doctor or lawyer. But their own knowledge was probably also very limited science wise.
Like I said before, even if they didn't really believe, they would still go to Church on Sunday. One of my granddads had a more religious family, and his brother was a Monk and sister a Nun.
My parents know the introduction of radio & TV. People get smarter, know more, probably also start questioning things more. And my generation, well, we had an excellent education. It's very hard to not start questioning things.
In the end, I think it starts deteriorating step by step. First it starts out with "Probably Jesus didn't really walk on water, it's just a matter of speech." And then it's other things. People get smarter, in their own lifetime but also over generations. It wouldn't surprise me if my grandparents and parents were more religious when they were younger.
Also, I was told there was a cinema where people would go to watch movies (before TV). The priest would go see the new movie first, and then tell everyone if they were allowed to go see that movie or not. People don't like that kind of control, and start rebelling against it. "The priest sees all the dirty things but we're not allowed".
At least for me, it feels like I started questioning things. I believed in God up until I was around 12. It also felt rebellious to know that it was all bullshit, while everyone else said it was real. But I guess it wasn't really rebellious since almost all boys of my age thought the same thing, especially at the age of 15.
Vatican II Is A New Religion https://www.youtube.com/watch?v=IX97Qg4DIJU
The Figures on the post-Vatican II decline https://vaticancatholic.com/29_Figures.pdf
In France particularly, the state is aggressively secular. They go out of their way to ensure no religion has any footing in any part of government and this occasionally makes it hard to be religious if you're unable to wear the expected garb or paraphernalia at school or at your government job.
The French have a long history of not wanting a single unimpeachable ruler. God just isn't welcome.
It’s really interesting to me how recently some “modern, first-world countries” were still dictatorships or still undergoing rapid democratization. France, Spain, and Korea are all dramatic examples, we totally don’t think of it in this context but at the start of the 80s Korea was a backwater under a military dictatorship, in the 50s France was a quasi dictatorship under de Gaulle with internal instability and unrest, Spain was under a fascist dictator until 1975, etc.
Plus there is the other factor that the structure of European cities and societies is much more amenable to protests and political action, where the US citizenry is atomized by design.
1. In Europe it is sort of the default state. Everyone belongs to the same Church. It is not really part of one's identity. American Christians are so splintered that being part of a Church means being part of a significantly smaller community and that plays a much bigger role in forming one's identity. The community aspect of Church is similarly more pronounced in the US for this reason.
2. American Jesus is your personal trainer, your protector, your personal cheerleader, your forever companion. European Jesus is technically supposed to also be those things but nobody really buys into it. The fervent belief in the efficacy of prayer is completely lacking. That gives people less incentive to go to Church.
I grew up in the Republic of Ireland during the 1980s when the vast majority (more than 90%) of people identified as Roman Catholics. I took it all very seriously (prayed multiple times each day, read the bible, a little theology, lives of saints, etc.) but my fellow Christians didn’t take anywhere near seriously: attending Mass on a Sunday, first communions, confirmations, weddings and funerals. While they might vote against abortion and divorce and send their children to Catholic schools, their beliefs didn’t really impact their daily lives.
Some of my parents’ generation believed in the efficacy of prayer:I always had my other and other relations praying for me during exams and if anyone was ever sick or having medical treatment, they would be prayed for. But most of my own generation didn’t share this belief in the efficacy of prayer. They certainly didn’t buy into the concept of Jesus/God being an integral part of their lives.
The Catholic church had the dominant position, so other than controlling educational, medical and other institutes, it provide its members with the same sense of community as that of Church of Ireland and other minority religions.
On the other hand, with its diversity of Christian churches, north of the border was much more like how you describe the US. The identity with religion was (is) much stronger as it usually corresponds with the individual’s national identity (Irish or British).
Note: Support for the Catholic Church in the Republic declined drastically in the nineties when the church lost its moral authority as news came out about how the hierarchy had facilitated child abuse and various other scandals.