text: The phrase "Kingdom of Heaven" is used in Matthew, while "Kingdom of God" is used in Mark and Luke. When Pilate asks Jesus, Jesus remains silent in the Synoptics. He does not wish to confirm the mistaken impression that he is a revolutionary, which is the text the party of the High Priest is peddling to Pilate so that Jesus can be executed as an enemy of Rome, but to deny his Kingship of the Jews would be to deny his very mission. John is clearer, perhaps for the reason you suggest.