But in answer to this objection, “If not before, yet why now, at least, does he not give some manifestation of his divinity, and free himself from this reproach, and take vengeance upon those who insult both him and his Father?” We have to reply, that it would be the same thing as if we were to say to those among the Greeks who accept the doctrine of providence, and who believe in portents, Why does God not punish those who insult the Divinity, and subvert the doctrine of providence? For as the Greeks would answer such objections, so would we, in the same, or a more effective manner. There was not only a portent from heaven— the eclipse of the sun— but also the other miracles, which show that the crucified One possessed something that was divine, and greater than was possessed by the majority of men.
Source: Against Celsus (New Advent)