Peter's denial was not just a personal weakness. He was in a leadership position, honored as the one who spoke for the group, and was second in command (when Jesus wasn't around). But his choice to publicly deny his place in the community at the side of Jesus had massive repercussions for the other disciples. They ran and hid, and from this point on in the Way of the Cross there is no mention of the disciples again in the Passion narrative. The sheep are scattered, routed, and demoralized. Peter's sin tore open the seems that held them together.
Megan McKenna, The New Stations of the Cross: The Way of the Cross According to Scripture
discipleship, influence, spiritual-leadership