Arguments about the "evidences of Christianity" have consumed the talents of believers and agnostics. These arguments have tried to give—or to deny—Christian belief a "foundation." Belief is rational, the argument goes, only if it is logically derived from axiomatic truths or is otherwise supported by "enough evidence."

Arguments for belief generally fail to sway the unconvinced. But is this because the evidence is flimsy and the arguments weak—or because they attempt to give the right answer to the wrong question? What, after all, would satisfy Russell's all for...