How is that effective given that the overwhelming majority of the US prison population identifies as Christian.
You can swap the word "prison" for all sorts of US locations and the statement will remain true. People identify as Christian all over the US....many are not.
Most folks are nominal Christians. You'll know the real deal by their fruits. Some folks give their hearts to the Lord inside prison. Some don't.
Prison isn't a catalyst for conversion. The drawing of Christ on the unrepentant heart is...whether they're in a prison, a palace or a Kentucky Fried Chicken.
It's why I said going to prison isn't everyone's "rock bottom". I've known folks that have gone to jail a dozen times....no life change whatsoever.