"It ain't ignorance causes so much trouble;
it's folks knowing so much that ain't so."
We humans make such mistakes regularly, and I won't apologize much for that one, even if I did somewhat mislead a few generations of students. Problems come in when you get people with large audiences asserting with confident ignorance equal to my own that Barack Obama is a Kenyan Muslim Mau-Mau socialist, or that the King James — or St. James — Bible is the true and exact text of Jewish and Christian Scripture and, hence, the infallible word of God. As an educated Fundamentalist will tell you, the usual party line is that the text of the Bible is "inerrant" in its "original autographs," and the KJV is a translation based on texts far removed from the originals. Other problems with the "inerrancy" issue I'll suggest below.
Somewhat more subtle problems come in when people accept not just unfactual facts but larger, untruthful Truths. E.g., there was a nice bit I caught while channel surfing where the Ed O'Neill father-character on Modern Family quotes Friedrich Nietzsche at the Rico Rodriguez kid-character to the effect that "What does not kill me, makes me stronger." The kid points out that a friend's grandfather (or whoever) had a stroke and survived it and is now a hell of a lot weaker. The Nietzschean dictum is obviously bullshit, but it's been quoted, with greater and less accuracy, by G. Gordon Liddy of Watergate fame, and, equally appropriately, at the beginning of Conan the Barbarian (1982).
Continuing with movies, we can look at the line from Cool Hand Luke, on a failure to communicate. There is a Wikipedia entry on this quote, where I am reminded and younger folk can learn that "What we got here is failure to communicate" comes from "the 1967 film Cool Hand Luke, spoken at different points in the movie first by Strother Martin (as the Captain, a prison warden) and later Paul Newman (as Luke, a young prisoner)." The line is often slightly misquoted, but except for fandorks — which I'm going to suggest as more sensitively gender-neutral than "fanboys" — except for fandorks, no one should much care. Of some actual importance, though, is that in the movie the line is a sick joke. Old Captain carries a bludgeon and communicates with Luke by beating on him.
What they got there is two stubborn people, Ol' Captain and Luke, who have very different desires, goals, and agendas. Ol' Captain intends to break young Luke; Luke doesn't want to get broken.
For me in 1967, the line in Cool Hand Luke mocked the centrist, often Liberal idea that many people knew that human conflicts stem inevitably from "a failure to communicate." Not so, Wise-ass Luke and The Powers That Be are communicating just fine; their conflict arises because they are in conflict: there are real conflicts of interest and desire.
Similarly, you well may have been taught and believe that earthquakes are caused by stresses resulting from the movement of tectonic plates — well, and so forth, for a scientific explanation of the mechanism, as currently understood, of what's going to destroy eventually much of my neighborhood and the surrounding California counties. Imagine that you get into a lively discussion with someone who'll grant you that movement of the plates and stress and all are the manner in which earthquakes occur, but that their actual cause in any given case is that God has removed his protection from his Chosen Americans and is allowing our punishment for abortion and homosexuality and other capital sins, probably starting in California.
The better you two communicate, the more likely one or the other or both of you will conclude, correctly, that you have radically opposed world-views and will never be able to convince one another of your position on earthquakes and other disasters, and on many other pressing issues. And it will be clear enough that the two of you will come, logically, to very different conclusions about allowing abortion and gay marriage, and what to teach in school starting with geology, biology, and SexEd and moving on to most everything else. You two will have to determine to "live and let live" in proximity to one another or to put distance between yourselves — anyone got a Texas secession petition? send it to me, and I'll sign — or one or the other or both of you get out the bludgeons or more serious weaponry.
If sane people know Barack Obama was born in Kenya, it should be simple to convince them otherwise: The birth certificate says Hawaii, and one must believe in an incredibly complicated series of lies, deceptions, and conspiracies to falsify all those records. If someone knows that "What does not kill me, makes me stronger," it's easy enough to show that, What they think they know / Just ain't so — at least not in this instance. Nietzsche's mental degeneration, whatever caused it, obviously didn't soon kill him (he was a long time ill), but it certainly made him no stronger.
Textual issues in the Bible are a bit more difficult to deal with than, at least out of context, a dumb-ass statement by a major philosopher. Still, scholars like Bart D. Ehrman can at least demonstrate in ways that should be totally convincing that however fundamental a Fundamentalist's beliefs are, s/he needs a more reliable translation than the King James to understand what the inerrant words are in the Bible's "original autographs," original transcriptions that are long lost.
What some religious folk know about the basic works of the faith frequently isn't exactly so.
The cause of earthquakes and other disasters — abortion, evolution, and the other religious/philosophical issues that bedevil us: these are more difficult.
When it comes to earthquakes and such I have to fall back on Occam's Razor and a possibly garbled, or totally apocryphal, quotation from Pierre-Simon Laplace. In the relevant version of the story, Napoleon Bonaparte noted that Laplace's theory of the origin of the solar system, indeed, Laplace's entire book, Exposition of a World System (1796), never mentions God. In the story, Laplace answers Napoleon, "I didn't need that hypothesis." Okay, if you don't need God to explain something, don't bring in God: it's, well, inelegant to do so.
And here is the problem.
If someone believes in an incredibly complicated series of lies, deceptions, and conspiracies is the nature of the world already, it may be quite a small step and quite logical step to believe that Barack Obama is a Kenyan and an American Mau Mau: a capital "E" Enemy agent (I'm talking Great Satan here) bringing to the heart of — to go full-frontal conspiracy whacko — the Zionist Occupied Government of the USA a Kenyan-socialist-Muslim Mau-Mau tyranny.
All of us face of the problem of "knowing so much that ain't so," and one of the horrors of life is that it's sometimes difficult to know what we don't know.
But part of the problem is ignorance: lack of training in logical thought of the sort the kid in Modern Family utilizes. You don't have to know what the hell "Occam's Razor," or "the Principle of Parsimony," might be; you do have to have some experience with disciplined thought. You do need experience dealing with evidence and enough of an education to know that most of the things of even our tiny planet you don't know and can't know. You do need to know to trust people who present without rancor or hatred or too much heat arguments that present evidence and make a coherent case.
It is ignorance that causes so much trouble, but indirectly, since it is some dangerous varieties of ignorance that allows "folks knowing so much that [just] ain't so."