We see that Peter wants to remind Christians of the truths (that he describes in verses 5 to 11) of the gospel, and how they should live holy lives.
Looking at verses 13 to 15. Peter’s words have an urgency that speaks to us today as well. He knew he was about to die. He is believed to have been over 60 when he wrote this.
This recalls the words of Jesus in John 21:18-19:
Jesus said, "Feed my sheep. I tell you the truth, when you were younger you dressed yourself and went where you wanted; but when you are old you will stretch out your hands, and someone else will dress you and lead you where you do not want to go." Jesus said this to indicate the kind of death by which Peter would glorify God. Then he said to him, "Follow me!"
Tradition holds that he was executed in
by being crucified upside down during the reign of Emperor Nero. He requested to be killed in this way, because he felt unworthy to die in the same way as Christ, his Lord and master. Rome
Verses 16 to 21 are a refutation of false teachers that Peter is confronting.
These false teachers were asserting that the Christian faith was based on myth, or “cleverly invented stories. “
Peter is saying quite plainly that Christianity is no myth. More specifically, what Peter is doing is reminding his readers to be faithful because despite what the false teachers he confronts say; the second coming of Christ is no myth.
He does this in two ways. In verses 16 to 18, Peter recalls that he has seen Jesus in all his glory. The synoptic Gospels of Matthew (17:5), Mark (9:7), Luke (9:35) give us the account of the transfiguration. Peter wants to show that this was an actual event, and not a story. He and the other disciples who were there on the mountain had had a glimpse of Jesus as he is in heaven, and Jesus as he will be when he returns. The prophets Ezekiel (Ezekiel 1:25-28) and Daniel (Daniel 7), and the apostle John saw the same thing (Revelation 1:1-20).
In verses 19 to 21, we see that as well as eyewitness testimony, Peter also reminds us that we have the written testimony of the prophets. The prophetic word of the Old Testament foretold Christ’s coming. These are the words of God Himself imparted by the Holy Spirit to humanity. It’s important to be reminded that they’re not human opinions or human words that humans tried to pass off as God’s words. True prophecy comes only from God, and all the prophets testify about Christ.
We now know that there are hundreds of prophecies or allusions to Jesus in the Old Testament. Maybe Peter had this in mind when he wrote these words.
In any case, on the basis of eyewitness testimony, and the testimony of prophecy, we have the assurance that Jesus will return, and in anticipation of this fact, we need to be faithful to him. This is a timely word. We also need this assurance.
What’s changed? People are still trying to tell Christians that our faith is based on myths or half-truths.
For example, certain schools of theology question key doctrines like the virgin birth, or the resurrection. They assert that this doesn't matter. You can take these things away, and still be a Christian by following the principles that Jesus taught.
The problem with this is that if Jesus isn't who we believe him to be, our faith is useless. We don't have a leg to stand on.
We could also mention authors of popular fiction, whose work implies that Christianity is based on some sort of far-fetched conspiracy.
As we've seen, Peter wants to assure those he wrote this letter to that their faith is no sham. Any claim that Jesus isn’t who we as Christians believe him to be doesn’t stack up. They had the promise of the blessing of sanctification in this life, growing to be more like Jesus, and the reward of eternal life. These promises apply to us too. Be encouraged to stand firm. Let there be no doubt in your mind that Jesus is who he claimed to be, both Messiah and God, and that he will do all that he’s promised.