[God] delights, it seems, in using trees, flowers, rivers, automobiles, friends, enemies, church buildings, paintings in order to announce His presence or to work out His purposes....There is something crude in the depiction of God intervening directly in the play, the clumsy deus ex machina interrupting the speeches of the other actors and upsetting the stage. How much more tantalizing the God who hints an lurks and cajoles hiddenly through and around the actors, even unbeknownst to them. It is the humble God who chooses so to act.
He has an absurd and distasteful desire who demands that God should shout "here I am" in response to his requirements. It is the I AM he would manipulate. I believe in signs and wonders, but it is "he who has an ear to hear" that will hear. It is the ability to see that such a person should ask for.
Now, to quote Mr. Yancey: "It takes the mystery of faith, always, to believe, for God has no apparent interest in compelling belief. (If he had, the resurrected Jesus would have appeared to Herod and Pilate, not to His disciples.)" (Rumors, p.41)He didn't appear to the pharisees either. He appeared to His friends...because His friends, though not without doubt, believed in Him already.