The point I was trying to make is that you can make headway by showing that a belief is detrimental without having to show that it's false. Otherwise modern secular legal restrictions on behavior wouldn't work. It's true that the person in question may not believe that the detriments are important compared to "eternal damnation", but at that point, they're faced with the choice of either complying with the law anyway, or else getting to spend some quality time at a facility designed to prevent people like them from repeating their behavior.
We can make headway, at least with society, to argue against the detrimental effects of a belief without having to show that the belief is false. For example, it is possible to make money off of a pyramid or Ponzi scheme (meaning, it is a true belief), but at the same time, the majority of people in the scheme are going to be harmed (or at least not helped) by it, and therefore such schemes can be legally shut down. The same thing goes with some of the more egregious effects of religious belief.
The reason why it works, jdawg, is because humans are wired for empathy. And while empathy can be short-circuited (you mentioned one way, "eternal damnation"; another is that it can sway people to empathize with someone who intends to abuse it), in general, it does what it's supposed to by making it difficult for humans in general to agree with doing harm to others. That's especially true when you talk about things which can be shown to have concrete negative effects, versus an abstract positive one which cannot be shown.
It's not easy to reverse that equation. It takes years for religious belief to manage it, and it only reliably works when there's no outside influences to detract from the process. That may have been true in the past, but it isn't true now. Look at the things that were permitted or required by religion in the past which have been successfully outlawed now, like slavery. In order to get the same kind of influence as religion had in the past, Christians have to attempt to isolate themselves and their children from the world, and that's getting more difficult practically by the day.
And also, many evangelists aren't really pushing "eternal damnation" all that much anymore. Some are, for sure, but in general it just isn't that effective, largely because society
is no longer structured to support it. It doesn't do a lot of good to argue that eternal hellfire awaits those who are not saved anymore, unless one lives in a society which actively pushes the whole concept, rather than passively accepting it as ours does.
So while those like your Bob Smith undoubtedly exist, they no longer have society standing behind them with a big stick, wordlessly discouraging detractors from going their own way. And by themselves, they simply aren't all that impressive.
I kind of went off-subject there a few times, but I hope this makes sense?