The apostle Peter here establishes the legitimacy of his desire to share with them the gospel message, by pointing out the veracity of the message itself. This was not mere hearsay he was repeating, not myth, but eyewitness testimony! Peter had himself witnessed the things of which he wrote.
How did Peter know that his Master was “our Lord Jesus Christ”? Among other events, he was present on the mountain when Jesus was transfigured before their very eyes (cf. Matthew 17:1-9). Peter heard with his own voice the words of the Father in heaven, “This is my beloved Son, in whom I am well pleased. Hear Him!” (vs. 5).
Peter was a witness of other events affirming the Lordship of Jesus. He was an eyewitness of Jesus’ resurrection from the dead (cf. 1 Corinthians 15:5). In fact, he proclaimed to the Jews on Pentecost this very proof, “This Jesus God has raised up, of which we are all witnesses” (Acts 2:32).
It doesn’t matter that much of Peter’s epistle is taken up in an exposé of false teachers and scoffers rather than a retelling of the simple gospel of our Lord. He was defending the faith, and equipping his readers to make their “call and election sure” (1:10).
