All Scripture is given by inspiration of God - This sentence is not well translated; the original πασα γραφη θεοκνευστος ωφιλιμος προς διδασκαλιαν, κ. τ. λ. should be rendered: Every writing Divinely inspired is profitable for doctrine, etc. The particle και, and, is omitted by almost all the versions and many of the fathers, and certainly does not agree well with the text. The apostle is here, beyond all controversy, speaking of the writings of the Old Testament, which, because they came by Divine inspiration, he terms the Holy Scriptures, 2 Timothy 3:15; and it is of them alone that this passage is to be understood; and although all the New Testament came by as direct an inspiration as the Old, yet, as it was not collected at that time, not indeed complete, the apostle could have no reference to it.
The doctrine of the inspiration of the sacred writings has been a subject of much discussion, and even controversy, among Christians. There are two principal opinions on the subject: That every thought and word were inspired by God, and that the writer did nothing but merely write as the Spirit dictated.
That God gave the whole matter, leaving the inspired writers to their own language; and hence the great variety of style and different modes of expression.
But as I have treated this subject at large in my Introduction to the Four Gospels and Acts of the Apostles, I must refer the reader to that work.
Is profitable for doctrine - To teach the will of God, and to point out Jesus Christ till he should come.
For reproof - To convince men of the truth; and to confound those who should deny it, particularly the Jews.
For correction - Προς επανορθωσιν· For restoring things to their proper uses and places, correcting false notions and mistaken views.
Instruction in righteousness - Προς παιδειαν την εν δικαιοσυνῃ . For communicating all initiatory religious knowledge; for schooling mankind. All this is perfectly true of the Jewish Scriptures; and let faith in Christ Jesus be added, see 2 Timothy 3:15, and then all that is spoken in the following verse will be literally accomplished.