If [Jesus] had given signs, as was demanded of him, they would have believed him. But at the the point where it really mattered, he held back. And that created the scandal. Yet everything depends on this fact...If Christ had documented himself with miracles, we would naturally believe, but then Christ would not be our salvation, for then there would not be faith in the God who became human, but only the recognition of an alleged supernatural fact. But that is not faith...Only when I forgo visible proof, do I believe in God.
-- Dietrich Bonhoeffer, God Is In The Manger