Mormon apologists for the most part, will never believe a killer blow can exist. Pacman over at FAIR said this exact thing when someone asked the TBMs what kind of evidence could there be to dissuade them from the Church's truth claims. He said point blank, "no amount of evidence." He was later compelled to go back and remove it because it was so telling. It pretty much proved the apologetic position was not grounded in reason. It was grounded in feelings. Nothing concrete that we know we know can get in the way of what a TBM feels he knows.
DCP knew this would appear intellectually bankrupt so he offered some unlikely scenario. He said if an affidavit were uncovered signed by Joseph Smith, which said the LDS Church was just a prank the whole time, then that would be enough to convince him. But I don't believe an authenticated statement like this would really do the trick. He would probably rationalize how Satan had temporarily been able to take hold of the "Prophet" in order to test the future saints. He would dedicate a dozen FARMS reviewers to tackle the subject for at least a decade while waiting to "find out all the facts" before drawing the obvious conclusion.
After all, it is what the spirit says that counts right? All physical evidence is irrelevant. It can only serve to strengthen testimonies, never destroy them.
God telling me he was just kidding.
Can you differentiate between self-induced feelings and whatever it is that you think "comes" from God?
Once I realized that it was impossible for me to do so, that pretty much threw a killer blow to one of my favorite apologetic lines. Ultimately it is circular reasoning anyway. It is from God. How do you know? Because the missionaries say good feelings wil be from God.
I mean even if you do hear voices in your head how do you know it is from God? Because the LDS missionaries tell us so and we believe it because we want to. Confirmation bias and a social need for acceptance helps us blind ourselves to the fact that we have been hearing voices and feeling feelings like these all our lives. We just didn't have anyone explain to us where they came from, from an objective, biological point of view. Nothing about the Mormon testimony cannot be rationally explained via science. Nothing.
The emotion factor is generally considered a mystery for humans and the LDS fairy tale version of it all makes many feel like, "Yea, wouldn't it be cool if that were true"? So once they have convinced themselves that their self-induced feelings of goodness is actuallyGod's way of "confirming" whatever it is the missionaries told them, it is all downhill from there.
The LDS manage to baptize the ignorant for the most part. I have had TBMs tell me flat out that they probably wouldn't have joined the church if they knew certain things, especially about the Book of ABraham. And the Church knows this too, which is why they keep the missionary discussions on a very superficial level.
This is why baptisms have taken a sharp nosedive since the internet age. People are more critically inclined and usually check up on things before swallowing the bait, hook line and sinker. Mormonism is not successful anymore for teh same reasons telemarketing scams are becoming less successful. They are forced to move to third world countries where people don't always have internet access.
“All knowledge of reality starts from experience and ends in it...Propositions arrived at by purely logical means are completely empty as regards reality." - Albert Einstein