According to Christian philosopher J.P. Moreland (as paraphrased by Melinda Penner), Christians are biased, but they are less biased than naturalists. In Melinda’s own words:
when a Christian deals with issues like science and faith, or the historicity of the Gospels, it’s fair to say that he’s biased in that he has a point of view, like everyone else. But a Christian’s bias doesn’t inform his conclusions in the same way that biases inform the conclusions of a naturalistic scientist–like Carl Sagan–or a liberal critic of the Life of Christ–like Jesus Seminar’s Marcus Borg.
And how, precisely, does it follow that a Christian’s bias doesn’t inform his conclusions in the same way that a naturalist’s bias informs his conclusions? Melinda continues:
Both Sagan and Borg start out, a priori, with the idea that there either is no God or that God does not directly intervene in the machinery of the universe. Their bias arbitrarily eliminates options before the game even gets started. These men must come up with conclusions that leave God out of the picture because their philosophy demands it. There can be no evidence for a miracle–whether the miracle of creation or the miracle of the resurrection–because miracles just can’t happen. A Christian is not so encumbered. He believes in the laws of nature, but is also open to the possibility of God’s intervention. Both are consistent with his world view. This means that he can follow the evidence wherever it leads him, unhindered by a metaphysical view that automatically eliminates supernatural options before even viewing the evidence.
So we have the following argument:
(1) Naturalists cannot consistently remain naturalists and conclude that a miracle (such as creation or the resurrection) occurred.
(2) Theists can consistently remain theists and conclude that a miracle (such as creation or the resurrection) occurred.
(3) Therefore, theists can follow the evidence wherever it leads while remaining consistent with their convictions, whereas naturalists cannot.
Is this a good argument? As it stands, it is not. For starters, the conclusion of the argument makes an unjustified generalization on the basis of a small and extremely biased sample set (two theistic arguments). There are other pieces of data that are equally relevant but are not embodied by the premises of Moreland’s argument. Consider the argument from evil. Classical theists cannot consistently remain theists and conclude that there is pointless suffering. Naturalists, on the other hand, can consistently remain naturalists and “follow the evidence wherever it leads” regarding the existence of pointless suffering.
Or consider so-called incompatible-properties argument for God’s nonexistence. Theists cannot embrace the conclusion of such arguments as theists, whereas naturalists have the flexibility to embrace or reject such arguments according to their merits.
In short, since Moreland’s argument does not even attempt to consider all available relevant evidence, its conclusion is unjustified. (I think there are additional problems with the argument, but I will stop here.)