I suggest these guidelines for reading scripture. Click on each for more a detailed explanation.
The New Testament is the final chapter in the story of God known to the Hebrews and the Jews through their scriptures. The Christian Bible is an interpretation of the Greek version of the Hebrew Bible, and "God in Christ" is a new understanding of the LORD God of the Torah, the Writings, and the Prophets.
Paul's letters were written before the New Testament gospels and argue against efforts by the Jerusalem church to require observance of Jewish law in the church. Paul proclaims salvation through faith in Christ crucified, says little about the teaching and ministry of Jesus, and claims authority for his gospel from the risen Lord.
The gospel attributed to Mark (all the New Testament gospels are anonymous) is the earliest New Testament gospel and supports Paul's view that faith, not Jewish law, is saving. The gospel presents Jesus Christ as the Son of God, tells the story of his itinerant ministry in Galilee, is critical of his disciples, and in its earliest version ends without a resurrection appearance.
The gospels attributed to Matthew and Luke are edited versions of the gospel of Mark with a "common sayings tradition" and other materials. The gospel of Matthew was written for a mostly Jewish church. The gospel of Luke (and Acts of the Apostles by the same author) were written for a largely Gentile church.
The gospel attributed to John was written for a Jewish church that understood Jesus as the Word of God made flesh, and as the Passover "Lamb of God" sent by the Father but rejected by "the Jews." The author freely revised the gospel narrative to defend the worship of his church.
The letters attributed to Peter and to James reveal the declining authority of these two apostles in the church after 70 CE. All four gospels and Acts of the Apostles verify Peter's leading role in the birth of the church, and Galatians and Acts confirm that James, the brother of Jesus, became the leader of the church in Jerusalem.
The letters and Revelation attributed to John concern the threats of false teaching in the churches and pagan persecution in the Roman Empire. The letters are anonymous but share in the teaching tradition of the gospel of John. Revelation includes letters warning churches in Asia and an extraordinary vision of Christ's victory over Satan.
The New Testament has more than one meaning. Its materials have at least three historical and literary threads woven together — the understanding of the author(s), early Christian interpretations, and church traditions concerning Jesus.
The authors of the letters and gospels of the New Testament drew on the scriptures of the Greek version of the Hebrew Bible to construct and interpret the story of Jesus and the church's witness to life in the kingdom of God through faith in Christ.
Our modern assumptions about history and biography make it hard to see that the New Testament restates and renews the Old Testament call to do God's justice and to love mercy, as a way of resisting imperial idolatry and oppression.