As the church spread, the new disciples needed encouragement and guidance. Since there was no compiled New Testament yet, the Lord used the apostles’ hands to give miraculous gifts to Christians (Acts 6:6-8; 8:14-19; 2 Timothy 1:6). These included special wisdom, special knowledge, prophecy, and confirming miracles (1 Corinthians 12:1-11). Then, the apostles and their helpers wrote letters to the Christians advancing their maturity and meeting spiritual needs. Most of these letters were by Paul, the apostle to the Gentiles (Romans 11:13): Romans, 1 and 2 Corinthians, Galatians, Ephesians, Philippians, Colossians, 1 and 2 Thessalonians, 1 and 2 Timothy, Titus and Philemon. Acts’ record of Paul’s missionary travels provides background for understanding his letters.
Hebrews helped Jewish Christians struggling with the transition from Moses to Jesus.
Letters to “general” (wider) audiences were James, 1 and 2 Peter, 1, 2 and 3 John and Jude.
The New Testament’s final book was John’s Revelation which shows how Christ gives victory over this hostile world. Though it uses vivid, sometimes difficult imagery, its purpose is to “reveal”—to unveil, to make known—important truths (Revelation 1:1). Certainly, it can be understood well enough for us to “hear” and “keep” its basic message (Revelation 1:3).
Christians considered these letters and the Gospel accounts and Acts as God-given.
If anyone thinks that he is a prophet, or spiritual, he should acknowledge that the things I am writing to you are a command of the Lord. (1 Corinthians 14:37)
Since Jesus promised to provide inspiration through His Holy Spirit, these writings were considered “Scriptures” (2 Peter 3:16; 1 Timothy 5:18 cf. 1 Timothy 4:1; John 14:26; 16:12-15; 2 Corinthians 2:7-16). Already recognized as authentic and authoritative, the books were collected over time to form the New Testament. With the Old Testament, they fulfilled the “all” statements by Paul and by Peter. “His divine power has granted to us all things that pertain to life and godliness” (2 Peter 1:3).
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. (2 Timothy 3:16-17)