In case some think I and other critics of Sola Scriptura are guilty of claiming Protestants think 'scripture' in 2 Tim 3:16-17 is exhausted by the (Protestant canon of the) Bible, consider the following:
Looking at the Bible itself may not seem
conclusive because it does not employ the distinctions to which we have become
accustomed. Its claims to authority tend to be general. It says that it is given
to furnish a man for ‘every good work’ (2 Tim. 3:17). (Noel Weeks, The
Sufficiency of Scripture [Edinburgh: The Banner of Truth Trust, 1988,
1998], 3)
We have the claim in 2 Timothy 3:17 that the
Bible equips a man for ‘every good work’. (Ibid., 7)
Further Reading
Not By Scripture Alone: A Latter-day Saint Refutation of Sola Scriptura