Faith, according to the Christian scriptures, is “being sure of what we hope for and certain of what we do not see.” So defined, however, doesn't faith look a bit like wishful thinking, or a stubborn refusal to allow one's beliefs to be judged at the tribunal of hard evidence? In short, doesn't this make faith seem like an irrational or, at the very least, non-rational way of acquiring and hanging on to beliefs?

Some people are content with the idea that their religious faith is somehow either contrary to reason or not subject to reason. The ancient church father Tertullian is often quoted as saying, “I believe because it is absurd.” The quotation is not accurate; but those who misquote him in this way often approve of the idea themselves. One who thinks this way about religious faith – that is, one who thinks that religious faith is irrational or non-rational and, furthermore, that it is still somehow okay or even a good thing to have religious faith – is called a fideist.

Fideism has been taken very seriously by a variety of philosophers and theologians. But a moment's reflection reveals that most of us will not be the least bit comfortable with it. Suppose you arrive at the doctor's office to be treated for a cold, and the doctor tells you she thinks it would be a good idea to remove one of your kidneys.