If there were a rock-solid argument that after reading it would de-convert people then all we'd have to do is take out ad space in local newpapers and on TV and then, presto, no more christianity. Not that there aren't many arguments that completely disprove christianity but there aren't any that would fit the description that you imply, simply because people will believe what they want to believe.

To elaborate on my prior post; the non existence of an abstract god concept has not\cannot be proven.  We do have enough evidence to reasonably rule out Yahweh as a real being.  Yahweh's story includes and\or revolves around a young flat earth, a flood that didn't happen, a stupid tower story, a talking donkey, a Jewish demi god, a preposterous desert to desert migration story, and many other pieces that contradict reality.  Knowing this, how does one continue to believe?...

First, ignorance!  Many people have not been educated on reality.  Some people have even been told by parents and clergy that science is wrong and works for the devil.

Second is dishonesty.  The easiest way to deal with the errors and contradictions of the bible and christianity is to deny, back peddle, or claim selective symbolism.  "Maybe the bible didn't mean 7 literal days, maybe days were like eras?"

Finally, and perhaps most common is simple disinterest.  Many christians only know what they've heard in the one church they've been to and have never even taken the time to read the bible.  I once asked a christian about the bear killing children for mocking the bald man story and the response I got was that of disbelief that the bible would have such a silly story.

There are many rock-solid arguments. Sadly the majority of the time I have seen them used, the religious fall back on "faith" and the conversation ends.

 I would say it's a yes and no situation.  Yes, there are rock solid facts.  Chief among them is this:

1) There is no scientifically or logically acceptable justification for belief in anything that could reasonably be called "god."

The next big one is this:

2) It is impossible to construct a coherent definition of a thing that could reasonably be called god which is both internally consistent and compatible with the observable universe.

So, what you're left with is a double whammy.  First, there's no concrete definition for the thing being discussed.  Second, there's no evidence to suppose such a thing could exist even if the definition were coherent.

It doesn't get much more rock solid than that, but most people don't recognize the significance of how rock solid these arguments are.  They don't think critically, and they don't understand basic epistemology.  Without a good scientific and logical background, most people will find these arguments unconvincing.  The thing that a few of you folks seem to be missing is that an argument can be rock solid and yet unconvincing.

Consider someone unversed in advanced physics.  You could spend hours showing them mathematical proofs of some of the wierder facts of quantum mechanics, but because they were not qualified to evaluate the evidence, they might well remain unconvinced.

The first error is argumentation. There are many kinds of argumentation. Only one of them is logic which is not properly argumentation at all. All over today and in the past other forms of argumentation have existed. Usually the techniques of rhetoric to sway opinion are considered the most important. They have nothing to do with the facts or logic. And you will find the most famous name in ancient Greece and Rome using them to sway opinion to facts they see as self-evident or at least self-serving.

In this regard, a good deal of preacher school time for ALL religions is taken up with learning and learning to present the accumulated centuries of such rhetoric. And they freely use techniques from competing religions. The purpose is to sway opinion not to deal with evidence in a logical manner.

As to facts themselves, a fact means nothing. It is how a fact is interprated that matters. Science is a consistent explanation of many different facts and is a discipline in itself. Most people do not have the slightest idea what science is but most of them firmly believe it is something that it is not. So you can't get any place there.

The best one can hope for is not atheism but doctrinal apathy. As I have said, it does not matter if people believe in a god or not. The problem is when they believe that god requires them to do or prevent certain things like abortion or short skirts. That is when they get nasty. People can believe god created everything and in Adam and Eve is not a problem until they take out after teaching evolution.

As I see it, promoting apathy is the most productive approach. I say this because that is what has happened with no particular effort at all in Europe. People are naturally susceptable to it. Once they don't care they are not motivated to break out the racks and start buring people.

For example dealing with a creationist. There is plenty of statistical evidence that what little that is taught of evolution in gradeschool doesn't change opinions. It should be easy to use that to convince an activist that he has already won the day and going after the remaining few is a matter of diminishing returns.

People like excuses to slack off. Give them excuses.

Yah, looking for the right argument is a losing game. No christian is even interested in any argument that would be in the slightest bit inconvenient. Hell, I have a friend who has a tshirt that says something along the lines of:

Faith is believing against the evidence and then watching the evidence change to fit belief.

Working against that type of nonsense is a losing game from square one.

On the other hand, over the years, I have found some traction with the literalism crowd simply by checking them on the bits that just do not make sense in any way what so ever. Here is one example:

The bible says that Solomon built the temple. What were the Israelites doing while this was going on? Having coffee I guess. But come on, every named item in that part is huge to the point of weighing several tons. Don't you think that just one time, someone would have said “Hey Solomon, that one looks kind of heavy, would you like a hand with that?”

Just between us and assuming that any of the bible is true, then what that part means is no different from any king in the middle ages having claimed to have built a castle when the truth was that he said “build a castle” and the king's word being law, it happened. Then said king took credit for the event.

For whatever reason, I have yet to meet a literalist who can see through the bloody obvious problem and come to the bloody obvious conclusion. I am guessing here but that might be a bit more than they can handle.

Apart from that, I have been reading a good bit of Bart Erhman recently and the guy with the tshirt seems to be pliant to some of his material. I got him to follow along with me the other night as far as the gospel of mark ending at 16:8. Then I mentioned that the other dozen verses were added in the tenth century. He seemed to take well to that.

I would not try that with the snake handlers from West Virginia though. Their whole deal is based on the extra verses.

Well treat2, I will grant that your point is quite on target. The only thing being that it is also a losing battle to require theists to prove anything.

He instant that you do, they have a whole arsenal of thought that they start quoting from. Now don't get me wrong here, I have never seen a theist thought on the matter that did not have at least one fatal flaw in it somewhere. However, since few theists have the intellectual capacity of an educated theologian, they almost never know what the problems with what they quote are. This does not stop them from the verbal diarrhea though.

As I said above, if you can start with the bits that they themselves are willing to admit are weak sauce, then you might be able to get them to go a bit further into the general territory of how the whole basis of what they are on about is weak to begin with.

That having been said, I suspect that it would take quite a while to do a full deconversion on a single theist. They have spent years at what they do and they will spend every Sunday from the moment that you start on them with their compatriots providing feedback on the matter. With some luck and a good couple of months, you might get a couple of them to start asking the hard questions but that is probably all that you can reasonably expect.

Now that is not going to stop me from trying. Step one might be getting them to accept that the last twelve verses of Mark were added in (or shortly before) the tenth century. If they bite on that bait, then I can work other angles such as the fact that the earliest couple of “bibles” predate the canonical set of books. As such, they do not include stuff that is standard today and include stuff that was later rejected.

If that opens a wide enough crack, then the sky is the limit. Among the lost works that did not make the cut is a text known as “The Secret Gospel of Mark” which makes it pretty clear that god jr. was probably gay. That should rock their socks.

On review I expect you will find the best arguments against Christianity among the followers of Judaism and Islam. I do not think that is what you want.