In response to the claim the apostolic teaching concerning the return of Jesus is a cleverly devised myth, Peter claims to be an eyewitness of “his majesty” (2 Peter 1:16b-18). Peter is referring to the Transfiguration of Jesus (Matt 17:1-8, Mark 9:1-8, Luke 9:28-36). In this well-known story, Jesus takes Peter, James and John to a mountain where the glory of God comes upon Jesus. God’s voice speaks, declaring Jesus to be his son and then Jesus speaks with Moses and Elijah.
In the Gospels the transfiguration calls attention to who Jesus really is: he is the Son of God and the fulfillment of both the Law (Moses) and the Prophets (Elijah). God’s voice sounding from a bright cloud declaring Jesus to be his son evokes both the theophany at Mount Sinai and Psalm 2, an important messianic Psalms.
In 2 Peter, the writer claims to be an “eyewitness of his majesty.” The noun Peter chooses for “eyewitness”(ἐπόπτης) only appears here in the New Testament, but has the connotation of someone that makes very careful observations. For example, God sees everything (2 Macc 3:39; 7:35; 3 Macc 2:21; 1 Clem 59:3) or the Emperor (IPerg 381).
What Peter witnessed was “his majesty” (μεγαλειότης, v. 16). This noun is also rare in the New Testament, but it is used in Acts 19:27 when the pagan Demetrius the Silversmith described the “great goddess Atremis,” she might lose some of her “majesty” if Paul’s gospel is left to grow unchecked. The word therefore refers to something ultimately impressive or awe-inspiring even in the pagan world. A similar word appears in v. 17 (μεγαλοπρεπής), although this word appears in the LXX to describe God himself (Deut 33:26; Sirach 17:3, “the glory of his voice”).
It is perhaps unexpected that Peter would answer the objection concerning the second coming of Jesus with a reference back to the Transfiguration. But as Thomas Schreiner points out, the transfiguration follows a statement about seeing “the Son of Man coming in his kingdom” (Matt 16:28–17:13; Mark 9:1–13; Luke 9:27–36).
In Matthew 16:21-23 Jesus predicts his own death and resurrection for the first time, immediately after Peter has confessed his belief in Jesus as the Messiah. In response to the surprising prediction that God’s Messiah was going to be killed when he went to Jerusalem, Peter rebukes Jesus (v. 22), and Jesus’ rebukes Satan and calls Peter a hindrance!
Jesus then declares to his disciples they must be ready to “take up their cross and follow him” (Matt 16:24-28). To a first century Jew, “taking up one’s cross” meant to be crucified by the Romans! Jesus warns his disciples that he will he be executed in Jerusalem, but also they must be ready for the same treatment. The assumed context of 2 Peter is just before Peter literally “takes up his cross” and die on account of his faith in Jesus.
Peter is therefore presenting himself as a prophetic witness to a foretaste of the glory of the Son of Man and his kingdom. Having raised the issue of prophecy, he goes on to argue that the prophets are reliable because they were inspired by the Holy Spirit.