" At this point, the notion of apostolic succession became very important. What was argued was simply that, if Jesus had some secret knowledge to communicate to his disciples—which in fact he did not—he would have entrusted that teaching to the same apostles to whom he entrusted the churches. If those apostles had received any such teaching, they in turn would have passed it on to those who were to follow them in the leadership of the various churches. Therefore, had there been any such secret teaching, it should be found among the direct disciples of the apostles, and the successors of those disciples, the bishops. But the truth was that those who could now—that is, in the second century—claim direct apostolic succession unanimously denied the existence of any such secret teaching. In conclusion, the Gnostic claim that there is a secret tradition with which they have been entrusted is false. "

― Justo L. González , The Story of Christianity: Volume 1: The Early Church to the Reformation (Story of Christianity)