Two of the best books I read last year were "Intellectual Morons: how ideology makes smart people fall for stupid ideas" by Daniel J. Flynn and "Hoodwinked: how intellectual hucksters have hijacked American culture" by Jack Cashill. The books detail how people like Ward Churchill can get away with stealing, lying, teaching fantasy as truth, etc. and yet, even after exposure, he will not lose followers, but gain them. Hundreds of other examples are given to illustrate the point that some things trump cold, hard facts. When those things are present, proof is rendered powerless and the best argument will fail.
One of the most powerful trump cards is race. This is not a black and white thing, but a worldwide issue; India's caste system comes to mind as does the Japanese/Korean racial divide. When race is introduced into the equation all other arguments and facts are tossed aside. This week in Detroit a State Trooper was acquitted of murder charges after he shot a homeless man who charged him, screaming and snarling, reaching in his pocket for a weapon. Race was introduced into the situation and people perjured themselves (proven by video tape of the scene) as they lined up divided by race. White people do this, too, when they paint pictures of blacks as lesser, violent, evil, etc. Every time you present evidence to the contrary your proof is trumped by their concept of race (although, have you ever seen a Klan rally or a group of Neo-Nazis stomping down the street and thought "Hey, look, there goes the superior race?" I thought not).
Closely allied to this is identity. We can choose race as our identity, but it is usually more complex that than. We choose identities as sports fans, or intellectuals (while these two are not not mutally exclusive it is exceedingly rare to find a professor of medieval poetry painting his body and wearing cheese on his head in Green Bay), or Christians, or atheists, or movie stars, ad infinitum. That sense of identity trumps proofs offered to us that we might be in the wrong. While in the two books mentioned above the target is the silliness of the left (in the main. Flynn goes hard after the right as well but not as extensively as he does the left) all of us need to do a gut check from time to time to see if our sense of identity (including race and religion) trumps truth. When it does, the results can be comical, farcical, or tragic beyond words.
Think of those who kill in the name of Jesus. Offer them proofs and scriptures and their sense of identity and mission will trump the truth. Offer churches scriptures to indicate that they have misunderstood the gospel and they will turn aside the scriptures as "isolated" and the verdict of two thousand years of Christian teaching as "quaint but outdated." They don't do this because they don't love Jesus; they do it because the Jesus they love is always sweet, always accepting, and always relativistic (relatively speaking). Their identity as Christians is based on that view of Jesus and no proofs offered them will change their mind. Just like a professor being questioned by a student, they assume the other is arguing from ignorance and darkness and that taints the argument before it begins.
It is critical that we get our sense of identity right. It is not enough to say that we are, first of all, Christians and then members of this or that group. We must make sure that the Jesus we are following is truly the one we find represented in Scripture (and in the church and nature -- those other two arrows). We do not get the Jesus we want, but the Jesus who is. We do not get the God we want, but the God who is.
James' word picture of looking into a mirror is still valid. In every argument, in every situation, especially when someone wishes to offer us "proof" that seems powerless or silly to us, we must check to see if our identity is part of the problem. Have we shut out truth to maintain our sense of who we are (including our sense of superiority over others)? Perhaps our prayers should include more "you are the potter and I am the clay" word pictures until we get into the habit of being shaped by God rather than shaping Him by our sense of who He should be, or would be, if He were us.