My best friend spent a decade in the klink. She has some interesting stories indeed. She has noted to me that prison ministries favor Christianity, at least in our state, so prisoners tend to have more access to Christian materials, pastors, and so on. She has also noted that actively Christian prisoners receive more privileges than nonreligious ones.
The implication, of course, is that many prisoners "convert" because it earns them more freedoms in the system, and because Christianity is what they have access to. This could certainly skew the current data about there being fewer atheists in prisons, if it could be demonstrated that prisoners convert out of expediency rather than genuine faith. If so, there could be folks who act Christian but are privately atheists.
But I don't know how one would measure that, or if anyone has ever done so. So maybe it's irrelevant.
Maybe it's the priests that know stuff like this:
I will profess my love for the Church.
The Church carries with it baggage. It is one holy and made of sinners. It is filled with hypocrites (and there is always room for one more).
Yet, it has survived the rise and fall of empires.
It has even survived and thrived beyond the fall of its own empire.
It traces its roots back to the holy land into all the people of the Old Testament and was founded by the Apostles and principally the Apostles Peter and Paul.
It has existed since then through history with a succession of Bishops of Rome as its visible head and source of earthly unity.
One in six people claim to follow it.
After Jesus died the Roman authorities killed Christians in the Colosseum in large numbers, not because they wouldn't deny the existence of Jesus (Whom the Romans knew existed), but because they would not deny that He rose from the dead and they had seen Him.
This Tradition follows for a few hundred years, though most of those killed no longer claimed to have seen Jesus after His resurrection.
Finally, the bishops converted the emperor (to some extent) and the Church was allowed to openly convert people. It was highly successful. Yes, to some extent the being a member of the Roman Church became compulsory, nonetheless.
So, what reason do we have to believe in Jesus?
It does not rest only on the four witnesses (the Gospels), which would be enough proof for most historians for the reason to believe historical events (it is way beyond what they require).
Nor is it because the NT Bible contains several eyewitness testimonies and those of the immediate followers of these. Enough, you could say, to prove any historical event, save for the miraculous, to any historian.
The Church itself, the Bible, and those who serve therein, all point to Jesus as not only have existed, but having risen from the dead.
And while I don't expect you to come running into my arms, I want to point out that both of us cannot be right.