An atheist friend asked me recently what reason there is to have faith in God.
Now, first, let us properly understand faith (my friend surely didn’t). Faith is, essentially, trust in what reason has revealed as truth and revelation has ratified, and vice-versa. To have faith is not to believe something for no good reason but to believe it for every good reason. Faith may be likened to a man who is deathly afraid of flying, but who nevertheless boards the plane, firmly reminding himself how unlikely it is to crash. He’s right and not irrational to believe the plane probably won’t crash — it’s a perfectly rational belief and he has every reason to believe it. Faith isn’t quite so much the believing but the accepting, the adhering of the will to that truth.
To ask what reason there is to have faith is to ask why reason obliges us to have faith. But if faith is simply the acceptance of truth, then the atheist is really asking (though he doesn’t know it), “Why does reason oblige us to believe that what reason has revealed as truth is truth?” Phrased this way, we see how silly the question is. It couldn’t be otherwise: to have faith just is to be reasonable. One may as well ask why triangles can’t have four sides.