2 Peter 1:12

In view of what he had written to this point, Peter explained that he realized his previous words were a reminder to his readers, not new instruction. 2 Peter 1:3-11 contain basic Christian life truth. His readers had heard this previously, but they, as all believers, needed a reminder of it periodically so they would not forget (2 Peter 1:9).

"We must not glide lightly over Peter’s concern about reminding the readers of already known and familiar truth. The history of the Church as a whole shows how careless the Church can be about clinging to divine revelation. So bad have things become in our own day, that the truth of justification by faith alone and of salvation as a free gift has already been submerged and lost among many evangelicals. The Reformation almost needs to occur again!" [Note: Hodges, 3:1:3.]