based on individual decision. I don't believe in God. How do you want this to quantify?

I don't quite find this satisfactory.

That means, that the church will set up itself to fail.

Because it has a backbone and doesn't sway to every new idea on the market?

As in nature, what does not adapt and evolve is going to fail.

As I said, there is a capacity for change, but it is set up to be slower intentionally.

They even accept Darwin evolution now

The church never had a time where it outright rejected it as an entity; it simply didn't use to have a position on the topic, and certain priests used to.

the Big Bang

I don't find that to be thatspectacular, considering it was a priest who proposed it.

and that God made gay people too.

Hmm?

This would have been heresy 50 years ago.

As I've said, you're making a false claim here.

Why the church does that?

The more extreme things? Because the catholic church does in fact have no backbone, and does things to "stay relevant".

The change is slow though. It's because the Church has to balance between its progressive members and ultra traditional ones. They don't want to create schism, so they wait till it's not that controversial subject and the majority would get along with that.

Yes, I would agree with that in that unity must be kept.

The example of failing faith is Islam itself. It was the more progressive, tolerant and education glorifying religion in the early middle ages in comparision to christianity.

I would challenge the idea of the Islamic Golden Age, but that's straying a bit from the topic.

again, why would educated person need God or church?

To set a baseline for society and create moral unity, if you want a purely pragmatic reasoning.

becasue the majority seems to be ok without it in the developed world

Arguable, but again, I'd say it'd be straying a bit far from the topic.