According to early documents, Mark received the source material for his gospel firsthand from Peter. In fact, many scholars believe it is possible to pick up on certain phrases throughout Mark’s work that seem to indicate colloquial, personalized reminiscences. In other words, Mark writes them down specifically in the way he heard Peter reminiscing about them. Three of these occur in the first chapter of Mark.
The first is in v.29 when Jesus leaves the synagogue to go to Peter’s house. The second is in v.30 in the specific actions of Jesus as he heals Peter’s mother-in-law. And the third is in v.35 in the description of Jesus rising before dark to go pray. According to the language experts, the construction of each of these phrases indicates firsthand, personal, intimate experience. It is a reminder that Jesus and Peter knew each other extremely well. Moreover, it helps to explain why Peter would allow, or perhaps even instruct, Mark to record things which clearly show Peter in a negative light.
In fact, one of these negative showings also comes up in ch.1 when Peter is presented as the ring-leader of those trying to control when, where, and how Jesus operates. Presumably, in relating this story to Mark, Peter is not afraid to be seen in a negative light because he is confident of how Jesus has worked in his life and transformed him into a new and different person. As he writes later in his first epistle, he knows that he has been healed and his soul has returned to its proper Shepherd in Christ because Christ bore his sins on the cross (1 Peter 2:24-25); as a result he is now one who through Christ has been restored and confirmed and strengthened and established in the eternal glory of Christ (1 Peter 5:10-11).
Peter is willing to be presented by Mark in all of his mess-ups because he knows that Christ loves and accepts him, warts and all. May we also remember that if our faith in is Christ, then what is most deeply true about us is not our mess-ups, but the fact that Jesus loves and accepts us, warts and all.