Although the New Testament letters appear after the Gospels in the NT, they were written well before them. We can date them by various means and the earliest probably appeared about 50 AD. By reading them, we can gain a good idea of the life of the early Christians, their successes, failures and problems and can learn much from them. We can see that they faced problems very much like ours.
Some like Romans were written to explain the Christian faith systematically. Others were written in response to questions that some early Christians asked the apostles. Yet others were fighting letters, sent to help Christians who were in danger of drifting from their faith. Every letter has its own particular message.
Briefly, we might say that the New Testament letters were intended to teach young Christians what to believe and how to behave. Some of them were Jewish and needed to learn that God does not save us because of what we have done, but because of what His Son has done. Others were Gentiles and had been brought up believing in many gods. They needed to learn that God is One. Jewish believers needed to learn that God’s grace did not mean that they could live as they liked but that love was the fulfilment of all the Old Testament laws. Gentile believers needed to know that the one God, unlike pagan gods, was righteous and wanted His people to live holy lives. So the NT letters meet different people’s needs.
Romans and Ephesians are the most systematic NT letters. Paul’s mind was very orderly and in these letters he explains what God has done. The death of Christ on the Cross makes it possible for God to forgive us. The resurrection of Jesus vindicated Him and brought new life into the world, which all believers can share. This means that they must live new lives according to the power which God has given them in the Holy Spirit.
The 2 Thessalonian letters, Philippians and Philemon are the most personal of Paul’s letters. He writes to young Christians , expressing his love for them and urging them to live lives worthy of their Lord.
Galatians and Colossians are “fighting” letters. Paul is trying to help young Christians who were in danger of moving away from their faith. The Galatian Christians were being taught by others that, having taken the first step by believing in Jesus, they needed to follow all the Jewish Law to become perfect Christians. The Colossian believers were being taught that Jesus was not the only Mediator between man and God and that they needed to be inducted into certain practices and secrets which only a few (called Gnostics, which means “knowledge”) could attain. In both these letters, Paul insists that we are saved by Jesus alone and by faith in Him alone.
The Corinthian letters are somewhat different. They deal largely with the questions which the Corinthian church put to Paul or the problems they were experiencing about which he had heard. The list in 1 Corinthians is surprisingly modern-divisions in the church, sexual immorality, Christians going to secular law courts to settle their internal disputes, idolatry, the role of spiritual gifts and the fact or otherwise of the Resurrection of Jesus. Christian truth comes out in all the answers he gives. 2 Corinthians also deals with forgiveness, the authority of apostles, and generosity in giving.
The other NT letters, by James, John, Peter and Jude are much less systematic, showing that every writer had his own style. They deal with general pastoral matters. Finally, Paul wrote some personal letters to Timothy and Titus, giving them advice on Christian leadership.
Although these letters were written a long time ago, as we go through them carefully, we can transpose them into our own age and find help in our Christian lives. They are worth reading!