Beloved, this is now my second letter to you. Both of them are reminders to stir you to wholesome thinking
1. Lest they should be wearied with the Second Epistle as though the first was sufficient, he says that it was not written in vain, because they stood in need of being often stirred up. To make this more evident, he shews that they could not be beyond danger, except they were well fortified, because they would have to contend with desperate men, who would...
Peter calls them beloved because a minister must show love and affection as well as doctrine; he writes the same things again without shame, for their safety matters more than his brevity. What the sanctified prophets spoke and what Christ commanded through the apostles deserve constant remembrance, for by meditating on these things the pure in heart feel the quickening virtues that make them lively and zealous in holiness.
AI summary
Commenting on 2 Peter 3:1-2
This second epistle, beloved, I now write unto you,.... This is a transition to another part of the epistle; for the apostle having largely described false teachers, the secret enemies of the Christian religion under a profession of it, passes on to take notice of the more open adversaries and profane scoffers of it; and from their ridicule of the doctrine of Christ's second coming...