Do you still not understand?  Twice in today’s Gospel (Mark 8:21),  Jesus asked his apostles,   “Do you not yet understand? . . . Do you still not understand?” (Mark 8:17, 21).   The answer is obvious.   The apostles thought Jesus was lecturing them about their irresponsibility in forgetting to bring enough bread for their journey (8:16).   But Jesus was after something much more important. When Jesus told them,  “Guard against the leaven of...