There's no way to truly prove or disprove the existence of an all-powerful deity acting behind the scenes simply by observing the scenes themselves, so to speak. Unless you can "peek behind the curtain," you can never know if a god is really there pulling the strings or not, not in the same way that you can know there are rocks and stars and grass outside. In our world, we have no way to "peek behind the curtain" we know of; we only know what we can observe directly and what conclusions we can draw from those observations. Because of this, ultimately, as long as you don't adopt religious views that actively conflict with what you can observe, you can always find room to believe that a god was responsible somehow without doubting what you've seen. Then again, no observation can force such a belief on you either. So, I think the most important question is, "What does believing in a god or gods do for you?"
By and large, most atheists and agnostics don't assert that they can disprove the existence of gods, more that they see no particular reason to resort to them to account for what they've experienced. Seeing something and then concluding that a god was responsible raises all sorts of other questions: Who is this god? What are their motives? How do they affect the world? Much of what we've found through observation is that the world around us follows strangely abstract and totally unbreakable rules, which apply without discrimination or apparent intent, and are so mechanistically reliable that you can predict the future in certain ways based on them. As far as we can tell, the rules don't change a whit no matter what rituals you perform, nor does nature seem to object to us gaming them and pulling little tricks with them and such like we do with our technology; they just sit there unfeelingly and stay exactly the same all the time. If you like Occam's Razor, you might find it more comfortable to just say, "With such inflexible, self-contained rules, why waste effort believing in something behind them?" This comes with certain challenges—you might find yourself contemplating Camus' question in The Myth of Sysyphus about why we should bother living in such an unfeeling world—but it also comes with many opportunities for its own special flavor of awe: confronted with a flower, you might find it more deeply moving to trust that the natural laws we know, despite their apparently simplicity and inflexibility, yet have such complex implications that one outcome they might lead to is the flower you see, than it would be for you to trust that a sentient deity created the flower and placed it there; the latter explanation would imply that the diety is an artist of cowing skill, but in a way that's a less surprising idea.
For some people, though, the pain that Camus gestured towards is not worth whatever they might gain from that worldview. If you trust instead that a divine force acts through the world around you, weaving a sense of underlying intent into your experiences, then you can know that, whether you experience hardship or pleasure, it was in some sense meant to be, and you can take comfort in that. (And how can any observation prove you wrong?) One of the most eloquent expressions I've heard of a version of this idea is actually in this talk by an imam named Mohamed Abutaleb on the Islamic concept of tawakkul, or complete trust in God; at the beginning of that talk, he says:
The theme that we're rolling with is "The Missing Peace: Your Quest
for Trust in Allah". And this is both a missing piece of our
lives—P-I-E-C-E—but it's also a missing peace, as in serenity and
tranquility, because when we lack this attribute, this issue of
tawakkul or trust in Allah...then we lose that peace and serenity
in our lives.
So, you can see immediately that without that kind of trust, he feels you are bound to feel restless and pained, discontent, doubtful, even depressed. Later in the talk he gives an example of a young person who feels they have to ace an important exam in order for everything to go right in their life after that, and despite making their best effort to study and prepare, gets a low grade and feels that their life is now ruined; he says that, if such a person has really made their best effort, they must trust the answer they have received from Allah in the form of their grade, relinquish their desire for total control of their life, and pivot to whatever follows without question. With a secular worldview, you have no guidance like this; if you feel your life is now ruined, well, maybe it is ruined, and whatever happens next is not the alternative God meant for you but simply another meaningless event in the random parade of billions of years of nature. Camus says,
All those lives maintained in the rarefied air of the absurd could not
persevere without some profound and constant thought to infuse its
strength into them. Right here, it can be only a strange feeling of
fidelity. Conscious men have been seen to fulfill their task amid the
most stupid of wars without considering themselves in contradiction.
This is because it was essential to elude nothing. There is thus a
metaphysical honor in enduring the world’s absurdity.
So, he too wants you to embrace whatever comes next, but not because it was meant to be—more as a kind of brave monument to how much it wasn't. I suspect that Abutaleb might pity Camus for holding this kind of perspective; he might feel that this "metaphysical honor" is a rather sad and mealy thing to strive for in the face of the deep peace and guidance he finds in tawakkul. Camus might call his tawakkul a kind of retreating or shying-away from the true challenge of human life. Who's right?
There is no scientific experiment or empirical observation that can pick between these perspectives (nor are they the only ones available). Choosing a worldview can't just be a straightforward matter of evidence or logic, but is necessarily one of desire and emotional resonance—in what spirit do you want to go forward?
