Revisiting that Glenn Lucke vs. the LDS Church post at Common Grounds Online, I found in the meta this challenge from a commenter, who I assume is Mormon:
Now I have a question for you......will you actually take the time to read the various links with material to answer your question?...... or will you simply move on to your next anti-Mormon question because you are, deep down inside, afraid of what the truth may reveal?
First of all, this is a cheap shot. It's a lousy way to have a genuine religious/spiritual conversation, and it's a disingenuous way to challenge someone's beliefs, because it immediately asks them to respond based on pride. It makes someone's response a matter of defending their own psychological state (am I afraid? am I defensive? am I kidding myself?).
I am guessing this tack works in the door-to-door missionary world, and the reason this approach by this particular commenter stuck out to me is because I had a Mormon missionary pull the same thing on me on my front porch. I wonder if this is a standard evangelistic technique, this put-them-on-the-defense sort of offense.
"Deep down you know this is true," the young man assured me after we'd gone back and forth discussing how the God of orthodox Christianity differed from the god of the LDS church, and suddenly we weren't talking about truth claims any more, but truth feelings. He proceeded to say, "Just pray about it. What could hurt in just praying and asking God to reveal to you that this is true?"
He almost had me. I'm not afraid of anything, my pride cried out. I accept your challenge, my fearful, sinful heart wanted to say.
But I knew better.
I said to him, with as good an analogy as I could improvise on the spot, "Asking God if the Book of Mormon is really true would be like asking God if he's a liar."
He didn't like that too much.
Christians, when discussing matters of faith and spirituality with unbelievers, I suggest you never tell them "Deep down you know this is true." I suggest you never push them to respond based on your appeals to their pride or defensive nature. That's a trick and it doesn't trust the Holy Spirit to awaken whom he will.
I personally will never say to an unbeliever "Deep down you know this is true" because I know that deep down they not only think the gospel can't be true, but deep down they hate it.