The disciples were clinging to their ship in the rough seas, much as we cling to our doctrinal beliefs to negotiate the rough seas of natural knowledge. But Jesus – who represents the divine desire for good – is not dependent on doctrine, but can be alive in a loving way even at the extremes of the church, where natural knowledge predominates. That's not easy for us to grasp, and the fact that the disciples were fearful shows the difficulty of grasping that higher level of spirituality.