Question

Hello Rabbi,
I had a discussion with a friend in which we reached the conclusion that there is no escaping the fact that a person cannot rely on the faith into which he was born, and must investigate with his own reason.
There is no escaping it, because a Muslim is also certain that Muhammad is the last prophet and that the Quran is a book from Heaven, and a Christian is certain that Jesus is the last prophet and that whoever does not believe in him will not receive his forgiveness. The idea is clear: everyone is convinced they are right.
And we came to the conclusion that since you see how people believe wholeheartedly and with strong faith in contradictory beliefs, there is no choice 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 rely on himself only after a rational inquiry in which he has properly learned the issues and his arguments are valid.
And here comes another insight: that a person who wants to clarify the objective truth needs to be sure, and it must be clear to him, that he conducted a completely objective inquiry, such that even if he had been born Christian or Muslim he would have reached the same conclusions,
because if he thinks he would not have reached the conclusions he currently holds, but rather that if he had been born Christian he would be Christian, that means he understands that the influence of the education and culture he calls faith is not objective, and therefore he cannot rely on himself.
Up to this point, is the reasoning correct?
 
And if we are right in this reasoning,
then basically the question is: okay, true, there is no escaping it and reason is what we have, but let’s admit the truth:
many of these topics are philosophically very complicated, very deep, and not simple. Even with your book, not everyone can read it and understand it, and in practice most people in the world have neither the talent nor the inner strength to conduct serious and careful inquiry into the great and fundamental questions. 
Some people can be honest with themselves and say: I do not have the ability to make this effort intellectually, especially when a person sees that smart, talented, and upright people have believed almost every possible faith, and that there are people much smarter than he is,
and a person can also conclude that they were more honest and upright than he is, and if he is honest with himself he can also admit that perhaps he is biased and unable to conduct this discussion properly.
So in that case his conclusion will be that he simply does not know!
That he does not have the ability to attain the truth; he does not have the talent or the inner strength. And if we speak honestly, we will see that most of humanity does not have this ability. The proof is that they do not deal with these questions, and those who do deal with them do not manage to do so seriously.
So if that is the case, the question is:
If a person is honest with himself, should he say to himself, “I do not know, and I have no ability to attain the truth”?
Does he have any solution by which he can attain the truth?
And could the solution be that such a person should examine who are the most talented, upright, and honest people he knows, and very simply rely on them, because presumably they have come closest to the truth out of the options he knows.
And always remain doubtful, since he himself does not have the ability to attain the truth.