Before Mark presents the traditions of his sources, he brings

an introduction of his own. In the most important narratives of the three traditions that Mark had, the three disciples James, John, Peter become witnesses of the events, 5:37; 9:2; 14:33.

Through the testimony of their progenitors, the Jewish Christians, the Baptist Christians and the Peter Christians are sworn to the three events of resurrection, exaltation and suffering as the three main points of the common confession of faith.