Errors in reasoning are often termed “fallacies.” One of the common ones I see in discussions with atheists and modern thinkers is known as “argumentium ad hominem.” This long, tedious latin phrase (often abbreviated as ad. Hom.) means someone raises an argument against a person, rather than their point; it argues “to the man” rather than too the argument. Most people discuss this as making a character attack, but this is only one type of this fallacy, unsubstantiated claims of bias, pop psychological analysis (such as the argument that Christians required moral absolutes because they “lack empathy”) and other similar phenomenon also qualify.
If you really want to understand the ad hominem fallacy, the easiest place to see it is in Washington, where it has become the modern politicians tactic du jour. For example, during the debates over Obamacare, one democratic senator suggested Republicans wanted the sick to die quickly, insinuating that their opposition to the bill was out of a lack of concern for the sick, and not, say opposition to rationing that might leave the elderly without care in the future, or concerns about the quality of care. Nor is this just a democratic phenomenon, just watch campaign commercials, and you’ll see nearly every politician is doing it. Yet, this example, explains why the ad hominem fallacy is so insidious, this immediately starts getting people questioning the motives, and not the actual arguments.
The problem with bias since post modern philosophy is that it is a charge that is often made unilaterally, males are innately biased, because they want to maintain a patriarchal society, conservatism is about maintaining power over others and Christianity is about keeping the money rolling into the church (despite the fact that most pastors serve small churches and aren’t making a fortune). While all of these things may be possible, it is equally true and possible that the feminists complaining in various books about patriarchy are more concerned with book sales and tenure than they are about society; liberals in politics similarly may oppose conservatives because they desire to seize power for themselves (as history shows, many of western histories great dictators have begun as “men of the people”). In other words, this is an easy charge to make, and can be applied to any camp.
When it comes to atheists, they often will argue that Christian interpret matters of science or Scripture according to a bias. If someone states that Evangelical’s have religious principles that influence their dating methods for the New Testament gospels, they probably do not consider that those who date the gospels after AD 70 are equally biased, because they assume prophecy isn’t possible, or they don’t consider the presuppositions derived from various German philosophers to be a bias. The reality is that New Testament studies, like all other fields of endeavor, is performed by human beings who bring their biases, presuppositions, experiences and, at times, our baser jealousies and desires for acclaim with us to the study. A claim of bias is a knife that cuts both ways.
So how do we handle bias? I would suggest that rather than allowing willy-nilly accusations of bias we require that the atheist(or anyone else) prove where the specific argument is flawed. if they are making a claim that something is a result of a bias without demonstrating it, then they should be dismissed as engaging in a fallacy.