JT Eberhard spoke at Grand Valley State University on Thursday, giving a talk entitled “Dear Christian.” It was about all of the standard arguments he has heard for Christianity and his answers to them. And the audience was most made up of Christians from the GVSU Campus Crusade for Christ, who co-sponsored the event.

After his talk there was a lot of questions from the crowd, most of them rehashing tired and incoherent arguments that we’ve all heard a thousand times. And I thought JT made a good point of responding to questions about basing one’s beliefs on faith by asking the questioners how they would respond to a Muslim or a Hindu making the same argument. After all, adherents to all other religions, which they consider to be false, defend their beliefs on the basis of faith as well.

The problem, as I’ve pointed out many times, is that faith defends all positions equally well and thus defends none at all. Faith provides no way to discern a true claim from a false one. A Christian who asserts the validity of his beliefs on the basis of faith has no way of disputing a Muslim or a Wiccan who asserts the validity of their beliefs on the basis of faith without undermining the validity of faith itself.

This is not true of science and reason, of course. In geology, for example, if you have two possible explanations for the depositional environment of a given formation you have a clear way of figuring out which one is true, of discerning the valid explanation from the invalid one. You do this through logical reasoning; each of the explanations will have a set of implications, usually phrased as predictions — if a given sandstone formation was deposited underwater, for example, it will have certain features that will not exist if it was deposited in a terrestrial environment, and vice versa. Each explanation leads logically to those predictions and we can then tell which one is the valid explanation by which one predicts the nature of the evidence better.

This is not possible when one makes a faith argument. If faith is a valid defense of Christianity, it is just as valid a defense of Islam, Hinduism or Zoroastrianism.