What does 2 Peter 3:16 mean?
Having praised the apostle Paul as a beloved brother speaking with wisdom given by God, Peter now acknowledges that some of Paul's writings are hard to understand. He also refers to Paul's writing as "Scripture." Both of these are important ideas.First, this reveals that at least some of Paul's letters were already considered the Word of God, even as early as Peter's day. Peter recognized that Paul spoke with authority and on behalf of the Lord. That helps to confirm that the New Testament writers and apostles were not competing with each other; they understood they were together delivering God's words to God's people.
Secondly, though, some of Paul's writings were hard to understand. We have certainly seen the same with Peter's letters. The best way to understand some Bible passages is not always clear or obvious. Unfortunately, according to Peter, there are those who see difficult passages as an opportunity to distort the overall truth of God's Word. Either due to ignorance or instability, they twist the meaning of a difficult passage to try to make Scripture say what it actually does not.
God takes His word seriously, and He holds accountable those who distort His meaning. Peter warns that destruction comes to those who do so.
This leaves us in a tough spot: how should we handle difficult-to-understand passages? Peter doesn't answer that question directly. However, the implication is that we should not use an obscure or difficult passage to contradict the clear teaching of other Scriptures. Reasonable and honest Christians may disagree quite strongly over the meaning of some things in the Bible. However, we cross a dangerous line when we distort the meaning of any passage to try to support our position on some theological argument.
The bottom line is that all of us must handle God's Word with respect, honesty, and a healthy dose of fear about getting it wrong—even when it's hard to understand.