The Greek adjective artios means complete, fitted, equipped, or proficient — perfectly adapted for a specific function. It appears only once in the New Testament (2 Timothy 3:17), but its single appearance is extraordinarily significant in establishing the purpose and sufficiency of Scripture.
Second Timothy 3:16–17 is one of the most important passages in the New Testament on the doctrine of Scripture: 'All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the servant of God may be thoroughly equipped (artios) for every good work.' The word artios implies complete sufficiency — not that Scripture is one useful tool among many, but that it provides everything necessary for the servant of God to be properly equipped. The related adverb exartizo (G1822, 'completely equipped, fully furnished') reinforces this: the God-breathed Scriptures make the believer thoroughly ready. In an age of competing authorities — experience, reason, tradition, culture — artios is Paul's counter-claim: the man or woman of God who is steeped in Scripture lacks nothing for godly living and effective ministry. They are perfectly fitted for every good work God has prepared for them (Ephesians 2:10).