But according to His promise we are looking for new heavens and a new earth, in which righteousness dwells. Therefore, beloved, since you look for these things, be diligent to be found by Him in peace, spotless and blameless, and regard the patience of our Lord as salvation;
just as also our beloved brother Paul, according to the wisdom given him, wrote to you, as also in all his letters, speaking in them of these things, in which are some things hard to understand, which the untaught and unstable distort [wrestle] as they do also the rest of the Scriptures, to their own destruction. - 2 Peter 3:13-16
Even Peter found some of Paul's inspired epistles "difficult to understand".
A guiding principle:
In Scripture, it is often the case that a writer will assert a thing and then immediately follow that with elaborating on what he'd meant by it.
Such is the case in the above by Peter.
He is not saying that what Paul had written had been hard for him to understand.
Not only did he still have Paul himself to explain things to him should he need that, Gal. 2: 7-9; but Peter himself was led of the Spirit to write the Scripture he wrote, 2 Tim. 3:16-17.
Besides, if Peter is referring to himself (especially after asserting that Paul had written to them about the reason for the delay in the Lord's 2nd Coming - His delay of His wrath prior to His return to bless Israel at last, given His Mystery longsuffering, Romans 9) - if Peter is referring to himself, then how would he be able to properly discern who had distorted what?
He is not referring to himself.
For he began that chapter with referring to a time after he would no longer be on this earth.
Peter is actually referring to a time after he and his fellow remaining Apostles, and the Apostle of the Gentiles, would no longer be on this earth.
The actual sense of that passage is that Peter asserts some things written by Paul are hard to understand...
He then follows that by elaborating on what he meant by that - that those who are unstable (who would therefore find said things hard to understand) would be distorting them, as has been done in Peter's and Paul's day, and even prior to them, with the other Scriptures also.
What he is actually doing is ending his thought on the exact same note he began that chapter with - a COMING distortion of things clear in Scripture on the reason for the delay in the Lord's promised return that some would be calling into question in THEIR instability, 2 Peter 3: 3-5.
The opposite of that being "ROOTED and built up" that is to say, being "STABLISHED in the faith, AS YE HAVE BEEN TAUGHT, " and as a result able to be "ABOUNDING therein with thanksgiving" Col. 2:7.
Which is the issue of knowing what's what; what goes where; and so on...
In contrast to the unstable in their ignorance are Peter and his readers' assurance - "but we, according to his promise..."
Thus, his words earlier, in...
2 Peter 1: 12 Wherefore I will not be negligent to put you always in remembrance of these things, though he know them, and be established in the present truth.
Another guiding principle being that of...
Just a matter of 2 Tim. 2:15's "study to" (spoudazo: be diligent to) being a bit more consistent where following the overall flow of thought of any Scripture writers complete narrative is concerned.
Acts 17: 11, 12.
In memory of Rom. 5: 6-8 - in each our stead.
