2 Peter 3:16 says that "the ignorant and unstable" twist Paul's letters "as they do the other scriptures." What does that phrase tell scholars about the letter's date?

Paul's letters already counted as scripture for this writer, and that points late. Collections of Paul's letters began to be made at the end of the first century, so a writer who ranks them with "the other scriptures" is writing after that. Most scholars date 2 Peter between 125 and 150 AD, the latest book in the New Testament.