(Disclaimer: This post is sympathetic to a certain subset of theists. I am not myself a theist, nor have I ever been one. I do not intend to justify all varieties of theism, nor do I intend to justify much in the way of common theistic behavior.)
I'm not adopted. You all believe me, right? How do you think I came by this information, that you're confident in my statement? The obvious and correct answer is that my parents told me so1. Why do I believe them? Well, they would be in a position to know the answer, and they have been generally honest and sincere in their statements to me. A false belief on the subject could be hazardous to me, if I report inaccurate family history to physicians, and I believe that my parents have my safety in mind. I know of the existence of adopted people; the possibility isn't completely absent from my mind - but I believe quite confidently that I am not among those people, because my parents say otherwise.
Now let's consider another example. I have a friend who plans to name her first daughter Wednesday. Wednesday will also not be adopted, but that isn't the part of the example that is important: Wednesday will grow up in Provo, Utah, in a Mormon family in a Mormon community with Mormon friends, classmates, and neighbors, attending an LDS church every week and reading scripture and participating in church activities. It is overwhelmingly likely that she will believe the doctrines of the LDS church, because not only her parents, but virtually everyone she knows will reinforce these beliefs in her. Given the particular nuances of Mormonism as opposed to other forms of Christianity, Wednesday will also be regularly informed that several of these people are in a position to have special knowledge on the subject via direct prayer-derived evidence2 - in much the same way that her parents will have special knowledge of her non-adopted status via direct experience when she wasn't in a state suitable to notice or remember the events. Also, a false belief on the subject could have all kinds of bad consequences - if the Muslims are right, for instance, no doubt Hell awaits Wednesday and her family - so if she also correctly assumes that her parents have her best interests at heart, she'll assume they would do their best to give her accurate information.
Atheism tends to be treated as an open-and-shut case here and in other intellectually sophisticated venues, but is that fair? What about Wednesday? What would have to happen to her to get her to give up those beliefs? Well, for starters, she'd have to dramatically change her opinion of her family. Her parents care enough about honesty that they are already planning not to deceive her about Santa Claus - should she believe that they're liars? They're both college-educated, clever people, who read a lot and think carefully about (some) things - should she believe that they're fools? They've traveled around the world and have friends like me who are, vocally, non-Mormons and even non-Christians - should she believe that her parents have not been exposed to other ideas?
Would giving up her religion help Wednesday win? I don't think her family would outright reject her for it, but it would definitely strain those valued relationships, and some of the aforementioned friends, classmates, and neighbors would certainly react badly. It doesn't seem that it would make her any richer, happier, more successful - especially if she carries on living in Utah3. (I reject out of hand the idea that she should deconvert in the closet and systematically lie to everyone she knows.) It would make her right. And that would be all it would do - if she were lucky.
Is it really essential that, as a community, we exclude or dismiss or reflexively criticize theists who are good at partitioning, who like and are good at rational reasoning in every other sphere - and who just have higher priorities than being right? I have priorities that I'd probably put ahead of being right, too; I'm just not in a position where I really have to choose between "keeping my friends and being right", "feeling at home and being right", "eating this week and being right". That's my luck, not my cleverness, at work.
When Wednesday has been born and has learned to read, it would be nice if there were a place for her here.
1I have other evidence - I have inherited some physical characteristics from my parents and have seen my birth certificate - but the point is that this is something I would take their word for even if I didn't take after them very strongly and had never seen the documentation.
2Mormons believe in direct revelation, and they also believe that priesthood authorities are entitled to receive revelations for those over whom they have said authority (e.g. fathers for their children, husbands for their wives, etc.).
3I have lived in Salt Lake City, and during this time was, as always, openly an atheist. Everyone was tolerant of me, but I do not think it improved my situation in any way.
Having been on an archaeological dig in Belize and having a wife that is a trained Mayan epigrapher, I am familiar with how archaeology is conducted and what is actually known about the subject, at least when it comes to central America. The answer is almost nothing, and my wife will hurt anyone except her grandparents that tries to claim that the Book of Mormon is referring to the Mayans. There is certainly enough evidence to say that it wasn't the classic or pre-classic Mayan (to begin with the dates are wrong, and the geography)
In case you didn't know claiming the Mayan were the Nephites is a decently common one among apologetics and it is the stupidest claim I have ever heard from them. It is much more accurate to say that we have no idea where the Nephites were, but that shouldn't be surprising if one actually goes through the Book of Mormon and tries to estimate how big the civilization was and where they lived. The answer is they were small and somewhere in southern Central America. Sorry, this is totally tangent to the discussion but you have my answer to the archeology objection now. It is not the standard one which I don't know what that is anymore. This, because they make things up instead of saying we don't know because apparently saying we don't know doesn't get rich donors to give you money.
um. I think I should clue you in on a basic doctrine of the LDS Church. There is no major religion on the planet that does not have complicating factors by being connected to LDS theology (excluding other christian restoration movements such as Jehovah's Witness or Scientology). God has revealed to every nation that portion of the truth that they were willing to receive and they subsequently fell into apostasy. I wasn't trying to hide that, it is taught in the first lesson given to investigators into the church by the missionaries.
D&C 93:33 is the main one. See also 93:29 and 131:7-8 for further information on the cosmology being talked about.
I love that word. I never thought I'd grow up to be an apostate but now that I have it has such a good ring to it. Even better than heretic.