Both Matthew and Mark record the miracle of Jesus walking on the Sea of Galilee. Matthew, however, includes two details that Mark does not. First, Matthew reports that the disciple Peter also walks on water when Jesus calls him out of the boat. Second, Matthew reports that the disciples all confess Jesus to be the “Son of God” after seeing the miracle. Since Mark leaves these details out, are the two accounts contradictory or inconsistent? Michael Wilkins, in The Gospels and Acts (The Holman Apologetics Commentary on the Bible), discusses the divergent accounts:

The parallel accounts (Mark 6: 45– 52; John 6: 15– 21) do not mention Peter’s venture into the water. This would be a remarkable thing to omit, if in fact both Mark and John knew it to be a fact. Does their silence call Matthew’s truthfulness into question? The key to explaining their silence is to recognize each narrator’s freedom to pursue different emphases. Matthew has repeatedly emphasized Peter and continues to do so throughout this section (e.g., 15: 15– 20; 16: 16– 23; 17: 24– 27). It is common for different narrators to draw out different details from the same or similar events. The different details often highlight each narrator’s specific purposes in writing.

In this case, we see Matthew’s unique emphasis on Peter’s leading role and his sometimes impetuous behavior. Peter is rebuked in this story for having ‘little faith,’ which is a common Matthean complaint about Jesus’ disciples (6: 30; 8: 26; 16: 8; 17: 20; France 2007, 567). Jesus will later teach his disciples about the faith that moves mountains (17: 20), a faith that would have kept Peter safe on the water had he not let fear get the better of him. Matthew’s inclusion of this incident provides an ‘illustration of the vulnerability of the disciple who allows doubt, the natural human perspective, to displace the faith which relies on the supernatural power of God’ (France 2007, 567). Another likely reason Matthew included this interaction with Peter is that Matthew reveals Jesus as divinely powerful and as the sustainer of his people (Morris 1992, 382– 83). Peter calls out to Jesus as ‘Lord’ (kurios), the same title used elsewhere to address Jesus with respect (e.g., 8: 21) or as a false declaration of faith (e.g., 7: 21). But here it means far more. Jesus is walking upon the water in the middle of a furious storm, something that elevates him above any other figure that Peter has ever known.

With regard to Matthew’s inclusion of the disciples calling Jesus “Son of God,” Wilkins writes:

This confession of Jesus’ deity is not present in the parallel accounts (Mark 6: 45– 52; John 6: 15– 21). If the confession really occurred, how could Mark and John choose not to include such an important saying? This is the first time that the disciples use the title ‘Son of God’ to address Jesus, and it is uncertain just how much they truly understand, for it was only at the resurrection that they became fully gripped with the radical truth of Jesus’ divine identity and ontology. The three accounts in the Gospels are witness to their growing, yet imperfect understanding of Jesus’ identity.

Mark’s account shows that the disciples still had only rudimentary understanding of who Jesus was as Messiah. Mark narrates, ‘They were completely astounded, because they had not understood about the loaves. Instead, their hearts were hardened’ (Mark 6: 51– 52). John’s parallel account says simply, ‘Then they were willing to take Him on board, and at once the boat was at the shore where they were heading’ (John 6: 21). Matthew’s eyewitness account focuses on both their growing yet imperfect understanding.

The three parallel accounts are historical testimony that allows us to see that, at the time of this event, it was still too much for the disciples fully to understand Jesus as the incarnate God. But their understanding is certainly increasing, because Matthew tells us that they worship him in response to his calming the sea. Recognizing Jesus to be God’s Son will be part of the continuing divine revelation that is expressed later in Peter’s climactic confession: ‘You are the Messiah, the Son of the living God!’ (16: 16). They are understanding more clearly that Jesus is uniquely related to God the Father, as those at Jesus’ baptism heard, and they will hear themselves at the transfiguration (3: 17; 17: 5).

To summarize, divergent accounts do not entail contradictory or even inconsistent accounts. Each of the Gospel authors were emphasizing different aspects of Jesus’ life. They each had different goals and purposes in mind when writing their biographies. Before we cry “contradiction” when we see differing accounts of the same events, we need to dig deeper to understand why there may be differing perspectives among the four Gospel writers.