When you try to explain something to a person, and they still believe in what they want to, even if you've given them evidence to prove your point, what is that person called?
I mean, a person with whom reasoning is pointless, because you know that whether or not deep down they know you're right, they will still shut their ears to what you're saying because they've decided what they're gonna believe in - what do you call them?
"Stubborn" doesn't do the trick.
The word blinkered is probably appropriate. Here is the definition from the Cambridge Dictionary:
A blinkered person is unable or unwilling to understand other people's beliefs, and blinkered opinions or ways of behaving show someone is unable or unwilling to understand other people
The word indicates that somebody metaphorically has their eyes covered: it is a reference to blinkers:
A pair of small leather screens attached to a horse's bridle to prevent it seeing sideways and behind and being startled
You could call such a person obstinate, stubbornly refusing to change one's opinion despite compelling reason or evidence.
In English, one very common word for a person who refuses to accept the truth of something in defiance of logic and/or evidence is denialist. We can also say that such a person is engaged in denialism.
Merriam-Webster defines denialist as follows:
: a person who denies the existence, truth, or validity of something despite proof or strong evidence that it is real, true, or valid : someone who practices denialism
We often modify denialist and denialism with words or phrases that indicate what the denialist refuses to accept. For example, someone who rejects the overwhelming evidence that climate change is occurring and is caused by human activity is a climate-change denialist. Similarly, those who dispute the scientific consensus concerning the seriousness of COVID-19 or the safety of vaccinations against the disease are sometimes said to be practicing COVID-19 denialism.
Please note that you can use denialist or denialism only when the focus is on the person's refusal to accept something that is true (or that you believe is true; see "one final note," below). You cannot use these terms when the focus is on the person's insistence on believing something that is false, unless you can reframe that insistence in terms of a denial of the truth.
For example, someone who claims that wildfires are the result of attacks by a secret group of Jewish bankers who control a laser that orbits the earth on a satellite may be a conspiracy theorist, an anti-Semite, a liar, an idiot, and/or a lunatic, but we wouldn’t normally refer to her as a lightning denialist, a careless-smoker denialist, or a gender-reveal mishap denialist. Likewise, although we theoretically could call those who dispute the validity of the Copernican model "round-earth denialists," in practice they are generally known as "flat earthers".
So what do you do when the focus is on affirmative belief in something false, rather than on denial of the truth, but you don't know of a term (like "conspiracy theorist" or "flat earther") that fits the specific context? Unfortunately, I don't think there's a single noun that will work in all cases. However, if you think the person is deliberately avoiding coming to terms with the truth, perhaps out of misplaced loyalty to an ideological system, you can accuse him of willful ignorance or self-deception. If you think he actually knows the truth but is only pretending not to, you can accuse him of bad faith. And if none of these quite apply but you want to emphasize what you see as a combination of foolishness and stubbornness, you can use the adjective "pigheaded," which means "stupidly obstinate."
One final note: Denialist and denialism are not neutral terms. I will call someone a denialist if I disagree with him and think he is being unreasonable, irrational, or dishonest. If I agree with him that the evidence for a given position is flimsy or suspect, I am likelier to applaud his well-founded skepticism than to accuse him of denialism. In fact, even if I strenuously disagree with him but do not think his position is unreasonable or dishonest, I will describe him as skeptical rather than calling him a denialist.
Here is an idiom and two adjectives expressing different nuances of meaning:
Doubting Thomas. It's an idiom meaning a person who refuses to believe anything until they are shown proof, but I am not quite sure if it suits you since you say that you've given the people evidences proving your point.
Bullheaded, 'very determined to do what you want to do, especially without considering other people's feelings'.
All the meanings are taken from the Cambridge Dictionary.
Ignorant is a choice word for me. If you say, "You are ignorant." Or, "You are ignorant to the truth." These mean essentially the same thing as stubborn however, a little more in line with ignoring facts.
