The Christian Bible is a tapestry of meanings.
Each letter and gospel in the New Testament has at least one author. That person may well have had access to written materials and oral traditions. Paul was informed of the oral teaching tradition of the Jerusalem church. The authors of the gospels of Matthew and Luke seem to have had the gospel of Mark and also a "common sayings tradition" as well as other materials. But each author of a letter or a gospel later was included in the New Testament not only drew on certain sources, but also made choices about how best to present these materials. We saw this in the way the authors of the gospels of Matthew and Luke modified the story of Joseph of Arimathea, as it is related in the gospel of Mark, to resolve an inconsistency in the earlier narrative.
More importantly, we can see that the gospel of Matthew was written for a largely Jewish Christian audience, because it emphasizes that Jesus is the fulfillment of Israelite prophecy. In addition, in the gospel of Matthew Jesus proclaims that the Jewish law is binding until the end of the age, and this commandment would apply to all Jews whether or not they accepted Jesus as the Messiah. It is also apparent that the gospel of Luke is written for a largely Gentile Christian audience. The gospel of Luke presents Jesus as a universal teacher and healer with roots in the Jewish tradition. Moreover, Acts of the Apostles, written by the same author, relates the story of the church from Peter's largely Jewish ministry in Jerusalem to Paul's largely Gentile ministry throughout the Roman Empire.
The gospel of John is so different from the first three gospels of the New Testament that it has been seen as a different source altogether. But it is probably best understood as the work of an inspired author, who freely rewrote one or more of the other gospels that were later included in the New
Testament. The free use of early church materials in writing a gospel is easier to understand, if we recall that these materials were not "scripture" until several generations later. Furthermore, these church materials from the first and second centuries are not reports by journalists or historians seeking to present the facts to a secular audience. The New Testament writings are sermons that proclaim the gospel. The gospels and letters of the New Testament were not written to report and explain, but to teach and persuade.
This is obviously true of the letters of Paul and the other letters written by Christian apostles, but it is also true of the earliest gospel. We cannot conclude because of its biographical form that it is the factual report of a journalist or an historian. A careful reading of the gospel of Mark reveals that it is a literary composition with a message. The author has made choices about how to present his material, and the narrative is not merely a record of events but supports an argument for what God has accomplished through Christ's crucifixion and resurrection.
In the later New Testament gospels we also see earlier interpretations in the life of the church, because we can identify sources that were used in composing these gospels. For instance, in the gospels of Matthew and Luke we see the earlier gospel of Mark and also a tradition of common sayings that is sometimes called Q or the "Q gospel." (Q comes from "Quelle," the German word for "source.") In the gospel of Mark we can see that the author often places one story within another, as he does with the healing of the bleeding woman (Mk. 5:25-34) that is inserted into the story of the raising of the daughter of Jairus. (Mk. 5:21-24, 35-43) Each of these healing stories has a history and meaning among Christians, which precedes its use by the author of the gospel of Mark in the particular way he presents them together. These are not simply events recorded by a reporter but are narrative teachings juxtaposed by an author and editor.
Thus, when we read the New Testament we must always assume there is an earlier strand of meaning and memory beneath the narrative or the teaching. The New Testament writings have a history, which does not merely concern dates and places where they were first composed or used, but has to do with what they meant for Christians at an earlier time in the life of the church. We read the four gospels together and construct our understanding of Christian faith based on the teachings in all of them. But earlier churches understood Christian faith by reading only one of the gospels. Moreover, churches existing even before the gospels were written relied on oral traditions, visits from apostles, and later on letters from apostles.
The earliest churches, however, simply read the Jewish scriptures to understand the good news in Jesus Christ. In the churches of Jerusalem and Galilee the scripture was read, as in the synagogues, from scrolls in Hebrew (and in Aramaic from commentaries called Targums). In the churches in cities of the Roman Empire, where Greek was the language of commerce and culture, the Jewish scriptures were read in the churches in Greek, using the Septuagint that was read by Jews in synagogues throughout the Greek-speaking world.
At this earliest stage in the life of the church, the teachings from scripture and fragments of memory and tradition concerning the life, death and resurrection of Jesus were woven into what would later be the teaching tradition of the church. Until 70 A.D. when the church in Jerusalem was destroyed, it exercised some control over this teaching tradition. Paul challenged the authority of the church in Jerusalem, but his arrest there suggests that the arguments in his letters, which we read today as scripture, were not understood as God's word by many of the earliest Jewish Christians. However, the destruction of the temple and the church in Jerusalem by conquering Roman armies decisively undercut the authority of Jewish Christian apostles from Palestine.
When the canon of the Christian Bible was authorized throughout the Roman Empire in the fourth century, all the materials included in the New Testament were from the Greek-speaking churches. The New Testament contains traces of the earliest life of the church, when it was predominately Jewish Christian and Aramaic-speaking, including affirmations about the death and resurrection of Jesus that were shared by all the churches. But much from the time closest to Jesus has been lost or revised in the light of subsequent events in the life of the church and the understanding of the New Testament authors.