Research limitations

Hello Rabbi,
I had a discussion with a friend in which we came to the conclusion that there is no escape and that a person cannot rely on the faith he was born with and must investigate with reason.
There is no escape, because even a Muslim is certain that Muhammad is the last prophet and that the Quran is the book from heaven, and a Christian is certain that Jesus is the last prophet and that anyone who does not believe in him will not receive his forgiveness. The idea is clear, everyone is certain of their rightness.
And we came to the conclusion that since you see how people believe wholeheartedly and with strong faith in contradictory beliefs, there is no escape but for a person to understand that just because he was raised and educated in a certain way does not mean he is right.
And in fact, a person can only trust himself after an intellectual investigation that he has studied properly and his claims are valid.
And here comes another insight: that a person who wants to ascertain the objective truth must be certain and clear to himself that he has made a completely objective inquiry, and that even if he had been born a Christian or a Muslim, he would have reached the same conclusions.
Because if he thinks that he would not have reached the conclusions he currently holds but that if he had been born a Christian, he would have been a Christian, it means that he understands that the influence of education and culture that he defines as faith is not objective and therefore he cannot trust himself.
So far, is the calculation correct?
 
And if we are right in this calculation,
Basically the question is: Okay, it’s true that there’s no escape and reason is what we have, but let’s face it,
Many of the topics are very complicated philosophically, they are very deep, they are not simple, even in your book, not everyone can read and understand it, and in fact most people in the world have neither the talent nor the mental strength to do serious and careful research into the big and fundamental questions.
Some people can be honest with themselves and say I don’t have the ability to make this effort intelligently, especially when one sees that smart, talented, and honest people have considered almost every possible belief, and that there are people much smarter than him.
And a person can also come to the conclusion that they were more honest and straightforward people than him, and if he is honest with himself, he can also admit that perhaps he is infected and is unable to conduct this discussion well.
So basically his conclusion would be that he simply doesn’t know!
He who does not have the ability to attain the truth does not have the talent or the mental strength, and if we speak honestly, it seems that most of humanity does not have this ability. It is a fact that they do not deal with it, and those who do deal with it fail to do it seriously.
So if so the question is:
A person who is at peace with himself is supposed to say to himself, “I don’t know and I have no ability to attain the truth.”
Does he have a solution where he can obtain the truth?
And could the solution be that that person needs to check who the most talented, honest, and sincere people he knows are and it’s very easy to trust them because they probably scored the best among the options he knows.
And always remain dissatisfied because he does not have the ability to achieve the truth.