Transfiguration: Peter writes with great earnestness (1:15), not only because he wishes to elevate his reader’s assurance, but also because what he writes is the truth. Peter’s message is the truth because he speaks as an eyewitness of Jesus’ majesty. At the mount of transfiguration Jesus manifested the “majesty” with which He will bring His kingdom. Peter was present there to see this sight and to hear the very utterance from the Father confirming Jesus as His beloved Son. Then Peter appeals to an authority even greater than his own eyes and ears: testimony of the Holy Spirit, which is Scripture.
Scripture: Peter appeals to the prophetic word of Scripture as the greater confirmation of his message of repentance. While the false teachers will arise who will contradict this message (2:1), Scripture speaks incontrovertibly the call to repentance, echoed by the Savior Himself (3:2). Hence, Peter exhorts us to rely on Scripture as the only lamp in the dark world of sin and deception.[1] Peter envisioned future generations to be full of false prophets who speak contrary to Scripture, who will deny the Master (2:1) and show their true identity through their fruits.[2] The pervasive message of Scripture points sinners to the Savior and calls them to the fear of the Lord, repentance, and the way of life.[3] Peter thus calls all to repentance (3:9), and that those who know the Savior must walk in holy conduct and godliness (3:10). Some twist this message (2:2-3), but Scripture remains unchanged and abides forever.
[1] “Dark place” in 1:19 is au-chē-ros (αὐχμηρός), meaning “dirty and miserable” (Louw-Nida) or “squalid” (Abbott-Smith). The world is indeed dirty, full of sin (1:4; 2:4-9; 3:7) and deception (2:1; 3:4, 16-17).
[2] False teachers are known by their fruits/lifestyle. This is seen in 2:13-15 as well as in Matt. 7:16-20.
[3] Fear of the Lord (Prov. 9:10; Eccl. 12:13; Acts 9:31; 2 Cor. 7:1; 1 Pet. 2:17), repentance (Psalm 7:12; Ezek. 18:30-32; Luke 5:32; 24:46-47; Rev. 3:19), and way of life (Deut. 30:19; Ps. 1:6; Rom. 8:2; Matt. 7:12-13).