The Apostle Peter
2 Peter 3:16ESV·traditional attribution

as he does in all his letters when he speaks in them of these matters. There are some things in them that are hard to understand, which the ignorant and unstable twist to their own destruction, as they do the other Scriptures.

John Calvin Reformed @genevareformer

16. In which are some things. The relative which does not refer to epistles, for it is in the neuter gender. It is in the feminine gender in some MSS. The authority as to the copies and versions is nearly equal. The difference is not much as to the sense, only “in which epistles,” reads better. So thought Beza, Mill, and others.

Matthew Henry Presbyterian @wholebiblehenry

The apostle, having instructed them in the doctrine of Christ's second coming, I. Takes occasion thence to exhort them to purity and godliness in their whole conversation: all the truths which are revealed in scripture should be improved for our advancement in practical godliness: this is the effect that knowledge must produce, or we are never the better for it.

Commenting on 2 Peter 3:11-18

John Gill Reformed Baptist @doctorgill

As also in all his epistles,.... From whence it appears, that the Apostle Paul had, by this time, wrote several of his epistles, if not all of them; and they were all written according to the same wisdom, and under the influence of the same spirit, as his epistle to the Hebrews: speaking in them of those things; of the same things, Peter had been...