II PETER 3:16

Q: Does this mean that some of the NT letters were already being considered as part of the Bible?

New Bible Commentary

The wording can be argued to include or exclude Paul's writings from the OT writings. But I Peter 1:10-12 and 2 Peter 1:19-21,3:2 “show that Paul's letters possessed all the qualifications for acceptance as Scripture (the apostolic authority of the writer and the guidance of the Spirit as he wrote). Paul was of course conscious of this himself (e.g. I Corinthians 2:13,4:17; II Corinthians 13:3-10; I Thessalonians 2:13).”

Oxford Companion to the Bible

The canonization process for the NT was driven by two factors: the analogy of an OT canon and adverse pressures from heretical groups. Between 100-150 AD oral traditions concerning Jesus were replaced by written gospels, which were treated on a par with OT as Scripture. From 150-190 AD, various Christian congregations drew up their own lists of authoritative books and began to standardize them among one another. By 400 AD the final NT canon was agreed upon by all.

Dictionary of New Testament Theology

Colossians 4:16 and I Thessalonians 5:27 demonstrate that Christian writings as well as the OT were read at services. II Peter 3:16 shows that Paul's writings were considered on a par with the OT. I Timothy 5:18 combines two sayings as “Scripture”: the first is from Deuteronomy 25:4 and the second one is a saying of Jesus found in Luke 10:7.

The Canon of Scripture by F. F. Bruce

A collection of Pauline letters is implied in this verse. It can be interpreted in two ways: these were an appendix to the OT writings, or as “the emergence of a new and distinct collection of 'scriptures'.” By about 96 AD, Clement of Rome in a letter to the Corinthian congregation places a quote from the Sermon on the Mount on a par with quotes from I Samuel and Jeremiah as being authoritative.

Tyndale Commentary on II Peter

James 4:5 uses “scripture” to refer to hallowed teachings not in the OT. Calling Paul's writings “scripture” at least means they were well on the way to being considered canonical. The superiority of apostles and evangelists to the OT prophets is implied in Ephesians 4:11 and I Peter 1:12.

Expositor's Bible Commentary

The most normal meaning of the Greek in 2 Peter 3:16 is that Paul's letters are considered to be fully Scripture. Contrary interpretations do not stand up.