2 Timothy 3:16–17 (ESV) … “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work.”
Timothy had known the Scriptures from childhood, so he knew that all Scripture was inspired by God. When Paul spoke of all Scripture, he was primarily referring to the Old Testament, since it was complete at that time. But the scope of Paul’s assertion would include any writing that was considered authoritative enough to be read in church meetings, which by the end of the first century would have included the four Gospels and Paul’s writings. According to 2 Peter 3:15–16, Paul’s writings were classified as “Scriptures.”
The Scriptures, affirmed Paul, were God-inspired. A translation closer to the original Greek would be, “All Scripture is God-breathed.” This tells us that every word of the Bible was breathed out from God. The words of the Bible came from God and were written by men. The apostle Peter affirmed this when he said that “men spoke from God as they were carried along by the Holy Spirit” (2 Peter 1:21).
Paul’s words here reminded Timothy that because Scripture is inspired and infallible, it is also profitable. The Bible is not a collection of stories, fables, myths, or merely human ideas about God. It is not a human book. Through the Holy Spirit, God revealed his person and plan to certain believers, who wrote down his message for his people. This process is known as inspiration. The writers wrote from their own personal, historical, and cultural contexts. Although they used their own minds, talents, language, and style, they wrote what God wanted them to write. Scripture is completely trustworthy because God was in control of its writing. Its words are entirely authoritative for our faith and lives. (See the discussion under 3:15 for the extent of the Scripture canon Paul may have had in mind.)
Scripture was profitable to every aspect of Timothy’s ministry:
doctrine—the content and teaching of truth, which must flow from and be consistent with Scripture. By calling the Bible “God-breathed,” Paul was identifying its divine source; by making it the source of doctrine, he was reminding Timothy of its authority. Doctrine that contradicted biblical doctrine was to be rejected, corrected, or replaced by accurate teaching.
reproof—rebuking those in sin. The initial impact of true doctrine involves the confrontation of false teaching and understanding. The offensiveness of some who teach biblical truth may have to be excused, but the offensiveness of biblical truth to error and evil requires no apology.
correction—helping people straighten out errors. In the area of correction, the Scriptures have two roles: (1) they provide a complete presentation of the teaching, where only part of the truth has been present; and (2) they provide for a right understanding and application where true doctrine may have been taught but has not taken effect.
instruction in righteousness (training in righteousness)—showing people how to please and glorify God. The ideal setting for doctrine includes the kind of preparation that minimizes the need for later reproof and correction. The nature of Scripture allows us to teach it confidently to our children and to learn from it ourselves.
The Bible is not purely a record of the past—the history of the Jews and then of the church. Rather, every story, every prophecy, every teaching, every admonition, and every command points beyond to the author, God, who came to us in Jesus Christ. God confronts us in the pages of his Word—telling us how much he loves us, how we can become his children, and how we should live to please him.
 Barton, B. B., Veerman, D., & Wilson, N. S. (1993). 1 Timothy, 2 Timothy, Titus (pp. 217–218). Wheaton, IL: Tyndale House Publishers.