The language of the Church has changed over time. The Bible contains no word for Trinity or Incarnation. It does not teach about the Immaculate Conception or the Assumption. These are all doctrines that have been developed over time. Which are true and which, if any, are false? That question brings us to the whole issue of authority. In an era in which notions of authority in general are in a state of confusion, this question of doctrinal authorityof who speaks for God and how we know that they do sopresses down on us like a stone.
Yet this is no new problem. Luther wrestled with the matter as he debated John Eck at the University of Leipzig in 1519 and found, to his surprise, that he was being driven by the logic of his own arguments away from the papacy. In writing hisEssay on the Development of Christian Doctrine, John Henry Newman found the matter irresolvable outside of the Roman communion. He thus swam the Tiber between completing the manuscript and seeing it in print.