Not even that, it's when you try to argue it.
I don't really care about casual Christians not understanding the Bible; they have their beliefs, they (maybe) read the English translation (if at all), they don't know about the history of the Bible. That's cool, because they're not the people who will really try to convert or convince people of God. Yes I do think that they're doing themselves a disservice by not knowing, but who am I to say what someone else's priority's should be? Most people would say that I need to go for a jog more often, but I tell them to fuck off.
Anyway, but when you try to spread the word... It's effectively the salesman without any training problem.