If humanity knew the truth about a god or gods--there would be absolutely NO reason to even consider discussing the subject.Thus,believers and non believers are the same.
There might still be a reason to discuss it, just like we discuss other truths... We would just be discussing how reality is, though, which is the same discussion... Believers and non-believers are two different things, however, and also similar in that we all want the truth. Or, I assume we all want the truth -- some people might just believe whatever serves them best.
The truth as I see it is that we humans in our present form are incapable of determining the existance of much outside of our own world ,let alone if god/s exist. If we were supposed to know-we would.Inasmuch as atheists have an opinion regarding god/s and theists have an opinion regarding god/s --what's the differance except one's negative and one's positive.They both hold strong opinions without proof one way or the other.
I agree that humans are flawed and maybe incapable of knowing ultimate truth, but I think they can make progress at least in challenging, and maybe eliminating, some of the fallacies and sheer nonsense through dialogue. I regularly attend a meeting of freethinkers, and as a Christian I can confirm your contention that there are dogmatic atheists. But not all are, and we have lively and friendly exchanges in that group.
It may be true that we are incapable of knowing, but I don't think that invalidates the conversation.