OK, I'll bite.
For the sake of discussion, what precisely do you mean by the word "truth?" Before I ask about the "truth" about "hell," I first must understand what it is you are attempting to convey.
I would add here, for the sake of discussion, that when I say the word "truth," I mean factual reality, reproducible or at least demonstrable. I can show you. So if "hell" is "truly" a "place" as you claim, you should be able to show me on a map.
Can you show me hell? Have you been there?
Since when black holes are demonstratable and evidenced to humans in stone age? Do you mean that the truth of the existence of black holes doesn't exist in stone age?
Truth can be independent of human knowledge. It boils down to how humans reach that truth. Hell (if exists) to today's humans makes no difference to black hole relative to humans in stone age.
So the question is rather, if hell exists how can you be able to reach this truth. More critically, how can you reach it on time. This latter on is critical because unlike black holes, the truth of hell concerns your own dead or alive.
Now for the sake of argument, we assume that hell truly exists.
If you want it to be evidenced, as if the stone age humans insist on seeing black holes before belief, then you leave yourself with the only possibility to get to this truth by seeing it yourself. That's the time when you enter it.
A more wise way to approach this truth is by examining the accounts of witnessing. Among the 100% humans who know for a fact that black holes exist, 99.99% of them don't have the evidence. They rely on trusting the scientists to get to this truth. It is so because the accounts of witnessing from our scientists are considered reliable. They are so reliable that we don't bother to even examine the evidence of black holes ourselves. We swallow with faith from the scientists that black holes exist for a fact.
That said, NT is based off those eye-witnesses who are willing to martyr themselves to stand witnesses for Jesus Christ. 10 out of the 12 direct disciples of Jesus were killed in conveying the truth of Jesus Christ.
So it is a scenario when the only way for you to get to a truth on time is to believing in accounts of human witnessing, and this truth concerns your own dead or alive, and there are said eye-witnesses sacrificed their own lives in order for the message to spread, what would you say?
Again and for the sake of argument, if Jesus is the truth, do you have a better way for this truth to convey?