I'll quote Tim Minchin here

"If you wanna watch telly, you should watch Scooby Doo
That show was so cool
Because every time there was a church with a ghoul
Or a ghost in a school
They looked beneath the mask and what was inside?
The fucking janitor or the dude who ran the waterslide
Because throughout history
Every mystery
Ever solved has turned out to be
Not magic"

Heliocentric model.

Cosmic distance and time. Light speed as a limit.

The geological age of the Earth.

Dinosaurs.

Evolutionary theory.

Continental drift.

The periodic table of the elements.

Quantum theory, including wave-particle duality.

The Heisenberg uncertainty principle.

Black holes.

Translative spoken word by the time a second hand account of the word of god becomes the word of the person speaking. Weird god never came back once we had verbatim recording techniques to address these inaccuracies.

Germ Theory

Diseases used to be associated with paranormal powers or the wrath of gods in most cultures. The discovery of microorganisms and advancement of medicine may be our civilization's greatest achievement.

Science deals with the natural, gods are by definition supernatural.

Science can not either prove or disprove existence of supernatural. It may only erode the reasoning why supernatural should exist.

That reasoning is subjective, and as such, there are no definite answers to your question unless we add additional constraints.

Religion exists for a number of reasons, but the primary purpose it serves an individual is as a foundation for their overall worldview.

"Faith" as many call it, serves to answer questions we don't have answers to.

Where did we come from? Why are we here? What happens after we die?

Religion gives us comforting answers to these questions, and as these questions are ultimately unanswerable, can do so in perpetuity.

Religion has also tried to answer questions that we didn't yet have answers for.

What are the sun, moon, and stars? Why are there tides? Why does it rain?

God was long accepted as the source of these things, and prayer was thought to be the best way have any influence.

But today we have answered basically all the major questions. We have a working model of the entire solar system, down to the weather on other planets. We figured out how to turn rocks into computers. All that's left is the unanswerable.

As for where we come from, we've filled in a lot of gaps. Evolution is now the accepted answer for where Humans came from, now the question is where life itself came from, and if there's life outside of Earth (and how much).

Philosophy has given us plenty of options for what our purpose is. There are plenty of ways to wrap your mind around your own identity without turning to the supernatural.

And our study of anatomy and neurology suggests that our conscious self ceases to exist after death, the only thing standing in the way of that belief is the very human tendency to be in denial of our own mortality.

Religion is deliberately non-falsifiable. No matter what scientific proof you can come up with, at the end of the day they just say God is fucking with us burying skeletons of creatures that never existed and such.

The fact that it needs to be constructed that way is frankly all the proof I need to toss religion in the garbage, but everyone isn't so cavalier about the disposition of their "immortal soul."

Honestly immortality and the very nature of God are both abhorrent to me. If religion were true, the best I could hope for is to be cast into a lake of fire and be destroyed, so I kinda win either way. Worst case is all religion is wrong but so is atheism and I have to spend eternity with an entity who is less of a malicious cunt than the Abrahamic god.

Sanitation.

Letter from Charles Darwin to Asa Gray (22nd May 1860)

With respect to the theological view of the question; this is always painful to me.— I am bewildered.— I had no intention to write atheistically. But I own that I cannot see, as plainly as others do, & as I shd wish to do, evidence of design & beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars, or that a cat should play with mice.

Source

Printing presses, industrialized education, and the industrial revolution.

Giving people en mass the time study and educate themselves.

The most reliable way to lose faith isn't through science, it's reading their holy text.

In general, nothing about science ever shakes a theist's faith, and I doubt it ever will. Reason being: the moment science breaks new ground, religion retreats further back into the unknown. As long as there is an unknown, theists will have something to take shelter from.

Evolutionary biology was the main one

Do we really need a scientific discovery to prove an existence that doesn't exist? I think the proof that's required is proof that God does exist and until that comes about, religion is clearly just a man made construct for the purpose of power and control.

Besides, I've given clear scientific examples to religious people before and they simply stated that it exists that way because god created it that way which is just the dumbest fucking thinking imaginable. You can't help those people.

What weakened religion is a long process going from the middle age to the modern world. It starts with the pope wars. It peaks with the religion wars in the XVIIth century. By this point the religious power was a political power like any other, but merely with a cultural hold on European populations. Which was the nail in the coffin.

During this period, the Church radicalised itself as a defense mode. Which solidified the laïcal mindset of the Lumières. Basically the church entered a cultural war against science because it feared it would lose controle.

Then the XIXth century happened. Monarchies got destroyed. And the Catholic Church got humiliated and destroyed as a political power. Socialism and communism appeared, and to state how progressive they were, they put the church in the same reactionary bag as the royalists.

In the middle of this are the liberals who don't care much about anything but profits. Si when democracy is on the rise, they are democrats. When royalty comes back, they praise the king. At least as long as they let them make good profits. And that's what the church doesn't let them do. Morale goes in the way of profit. It forbid slavery and exploitation. It's against science. It promotes charity. That sucks balls for the liberals. But order is good, so why not being a believer but without the problems?

It's not science that made religion recess. It's bad political decisions and alliances. Many renowned scientists were believers. Many still are. But somehow the religions are rejecting science because it doesn't go into litteraly what their old fantasy book wrote. It's a shame because religions could easily make a humanist evolution if they had the political will to do it.