The word refers to an agreement, pact or "covenant" (the Hebrew word for covenant is bĕrît, translated in the Greek Septuagint Bible by diathēkē, which in the secular world refers to this covenant or agreement related to death, thus to the testament). In the history of Israel, it is first the covenant established by God with Noah, then Abraham, and then David by which he promises his particular support. But the most important covenant is the one made with Moses at Sinai by which Israel becomes God's people.

It was not until the 7th century BC that we heard about the "New Covenant" (Jer 31) :

31 The days are coming, says the Lord, when I will make a new covenant with the community of Israel and the community of Judah. 32 It will be different from the covenant I made with their fathers when I took them by the hand to bring them out of the land of Egypt. They have broken my covenant, but I am still their master, says the Lord. 33 This is the covenant that I will make with the people of Israel after those days, says the Lord: I will put my instructions in their hearts and write them into their being, and I will become God for them, and they will become a people for me.

This new covenant is above all a renewal of the covenant. It is in this spirit that Paul speaks of a "new covenant" in his letters (2 Cor 3:6; Gal 4:24-26). And the death and resurrection of Jesus was interpreted as the renewal of this covenant with a new dimension ("This is my blood, the blood of the covenant, shed for many": Mk 14:24; Mt 26:28; Lk 22:20; I Cor 11:25). It was only later, following conflicts with the Jews who had become hostile, that the term "New Covenant" or "New Testament" was seen as a replacement for the old covenant or old testament, which was now considered obsolete.

It is only in the second century that Christians use the term "New Testament" to designate the group of writings that concern them, which in contrast leads to designate the writings concerning Israel by "Old Testament". It would take several more centuries to agree on the group of 27 books that now constitute a normative and canonical collection.

Very early on, the need was felt to offer support to potential readers of the New Testament. First, at the end of the second century, there were those texts called "Prologues", attached to the gospels, which gave some detail: the author and the circumstances of composition, and then this fragment known as the Muratori. In the early 5th century, a monk from Antioch known as Hadrian or Adrien wrote a hermeneutical treatise to guide the reader: Introduction to the Holy Scriptures. Several other works would follow until the publication of the first works considered scientific (between 1689 and 1695) by Richard Simon, whose conclusions would scandalize Protestants and traditionalist Catholics.

From the late 18th century through the 19th century, various introductory works to the NT were highly speculative in seeking to attribute the NT to various schools of thought in order to reconstruct the evolution of early Christianity. Today, introductions to the NT seek instead to simply provide information about each book.

At the time of Jesus, the Jews were aware that they had a number of sacred texts: the Law, the Prophets and certain other writings. This is what the early Christians mean when they speak of the Scriptures. But they themselves took a long time to put something in writing. Why did this happen? First of all, Jesus himself did not write anything and never asked to write anything. Secondly, the coming of the kingdom inaugurated by Jesus did not depend on any writing. Finally, the early Christians lived in an apocalyptic atmosphere where the return of Jesus was imminent, so there was no perceived need to write for a future generation.

1. The Letters

   The letters were born out of a pressing pastoral need. Paul was an itinerant apostle proclaiming the gospel in various places, and letters were his way of keeping in touch with all the new converts, especially when he was entrusted with problems to solve (this need probably did not exist for all the apostles who remained in Jerusalem and could communicate orally with their audience). Thus, in the 50s Paul produced the first Christian documents with his first letter to the Thessalonians, followed by his letters to the Galatians, Philippians, Philemon, Corinthians, and Romans. Each letter is explained by a particular context, and each time Paul adapts his language to his audience.

   But from the mid-60s onwards, the death of the great Christian figures and the disappearance of a generation who had been eyewitnesses to the Jesus event or who had experienced his resurrection, created the need for more permanent documents. Thus, a number of letters appear, not necessarily written by Paul himself, but claiming his spirit and authority. Several biblical scholars assign to this category the second letter to the Thessalonians, the letters to the Colossians, Ephesians, and the pastoral letters (1 and 2 Timothy, Titus) which would have been composed between 70 and 100, after Paul's death. Confronted with a certain number of problems, disciples or admirers of Paul would have taken the initiative to propose their opinion which they believed to be faithful to the spirit of Paul. The tone of these letters is more universal and permanent.

   The letters of Peter, James and Jude also belong to this post-70s period, according to many biblical scholars: the authority of great Christian figures is used to address the problems of a new Christian generation. Together with the epistles of John, they were given the title "Catholic" or "General", an appropriate term when addressing the universal church.

2. Gospels

   Literary genres other than letters also appeared during this period, the best known of which is the gospel. According to biblical scholars, the gospel according to Mark was written in the middle of the year 60, or shortly after 70, providing an account of Jesus' actions and words that was absent from the letters. This account is marked by the accumulated experience of the decades following Jesus' departure. For example, Mark emphasizes suffering and the cross, a likely echo of a persecuted community. In addition, Jewish customs sometimes need to be explained that Christians from the Gentile world do not know. The gospels of Matthew and Luke, written ten or twenty years later, add to Mark's account a collection of Jesus' words known as the Q Document, in addition to coloring it with an experience specific to each of their communities. An even different tradition takes shape with the gospel according to John, written around 90 or 100 AD. Despite their diversity, these gospels seek to preserve the memory of Jesus for a late first-century audience, when eyewitnesses have disappeared.

   None of the gospels mention who wrote them, and it is quite possible that they were not written by the person to whom they were attributed in the second century, i.e., John Mark, a companion of Paul and Peter, Matthew, one of the Twelve, Luke, Paul's companion, John, one of the Twelve (but that John Mark is the author of the first gospel, and Luke the author of the third gospel and Acts seems likely according to biblical scholars). This does not diminish the claim that these writings faithfully interpret the thought and work of Jesus as witnessed by the first generations of witnesses.

3. Acts; Revelation; Other Literary Genres

   The Acts of the Apostles is an example of another literary genre more permanent than the letters. According to its author, Acts is the second part of a work that began with the gospel and ends in Jerusalem, and now witnesses the expansion of the gospel out of Jerusalem, to Samaria, then to Galilee and to Rome, the center of the world. We are no longer looking up to heaven waiting for the return of Jesus, but we are now in the midst of missionary activity, as the Gentiles of the whole world are called to receive the gospel. All these events are not coincidental, but are guided by the Spirit given by Jesus.

   The Book of Revelation (The Apocalypse) represents another literary genre after the year 70. This genre has its roots in Ezekiel and Zechariah, and becomes popular in the second century BC with Daniel and continues in the early modern era after the destruction of the temple in Jerusalem with 2 Baruch and 4 Esdras. The word "apocalypse" is derived from a Greek word that means: revelation. This genre appears in a world where God's people feel persecuted and see their faith in God's control of history put to the test. So this vision is developed that encompasses heaven and earth, and witnesses the battle between God and the evil spirits, with the assurance of God's final victory. This vision uses a wealth of symbols. The book of Revelation presents messages addressed to particular churches, where God's attributes take on a symbolic form, beyond the rational world, reminding late first-century Christians that God's kingdom is much larger than the history they are witnessing. It is therefore a message of hope, and an assurance that, despite present persecution, God will give them victory.

   There is another literary genre, which has been packaged under the term "letter" because it was the dominant genre, but which was not really so. Some writings are closer to the homily, like 1 Peter, or the diatribe, like James. And there is the special case of the "epistle" to the Hebrews, a writing that has the conclusion of a letter, but whose beginning does not indicate to whom it is addressed, the Hebrews as addressee coming from an early biblical scholar after the analysis of its contents. It has a typically Hellenistic or Alexandrian oratorical style and develops a profound Christology of the Son of God. The distance between the style and theology of this "letter" and the letters of Paul is remarkable. As for 1 John, it does not have the format of a letter and does not mention John, and is therefore difficult to classify. It shows the application of the themes of the 4th gospel to a community threatened by schism.

   Thus, through different literary genres, Christians after 70 continue to address the various problems that arise in the various communities, but they do so in a way that the answers they provide can be applied to other communities and times. So, as easy as it is to date Paul's early letters to within a few years, if not a few months, it is difficult to date this literature after the 70s.

How did these writings, composed between the years 50 and 150, come to be considered on the same level as the Scriptures of the Jewish world, and therefore sacred and authoritative to the Christian faith? The process by which these writings were preserved is not fully understood, but a number of factors can be pointed out.

1. First, apostolic origin, real or putative

   There are letters that were not physically written by Paul, Peter or James, but became important because they claimed the name, spirit and authority of the apostles. The gospels were ultimately attributed either to apostles (Matthew, John) or to apostolic men (Mark, companion of Peter, Luke, companion of Paul). The Book of Revelation, containing visions of a prophet called John, was welcomed in the Western churches because it was assumed to have been written by the apostle John. The epistle to the Hebrews was more complicated: the Western churches did not believe it was written by Paul and excluded it from their first list of writings, while the Eastern churches accepted it as a writing by Paul; it was not until the 4th and 5th centuries that the Latin church included it in its list.

   Nevertheless, the criterion of apostolicity is not sufficient in itself. For example, there are letters of Paul that have not survived, such as the one mentioned in 2 Cor. 2:4 or the letter to Laodicea (Col. 4:16), or letters that are said to have circulated falsely under the name of Paul (2 Thess. 2:2) and that do not seem to differ from those called deutero-Pauline. The Gospel according to Peter was rejected because of its content by a bishop, without any real debate about its author. Finally, many of the apocryphal gospels were rejected, even though they bore the name of an apostle.

2. Second, importance of the addressed Christian communities

   The Christian communities played an important role in preserving documents addressed to them. For example, why is there nothing about the communities of Jerusalem or Palestine, when they could be the source of some of the traditions of the gospels and Acts, if not because they were completely shaken by the Jewish revolt against Rome? Conversely, Antioch welcomed the gospel of Matthew, where it seems to have taken root, just as the churches of Asia Minor (e.g., Ephesus) and Greece (e.g., Corinth) welcomed the letters of Paul, the gospel of Luke and his Acts, and the gospel of John. The church in Rome received Paul's letter to her, and perhaps the letter to the Hebrews and the gospel of Mark. All of these churches are important because they are often associated with an important apostolic figure. This explains why minor works, such as the letter to Philemon or the letter to Jude, have been preserved that would not otherwise have been retained; they have benefited from the aura of the milieu that kept them.

3. Third, conformity with the rule of faith

   The word "canon" or "norm" defines first what constitutes the set of fundamental and essential beliefs of Christian communities, before designating the collection of writings that are normative for the Christian faith. The importance of this conformity to what constitutes the core of the Christian faith can be illustrated by the story of Bishop Serapion of Antioch (c. 190), recounted by Eusebius of Caesarea, who began to forbid the reading of the Gospel of Peter when he saw that some Christians were making a Docetist reading of it, denying that Jesus really suffered and died on the cross; because all this contradicted the four gospels and the letters of Paul putting the cross and death of Jesus at the heart of the faith.

But these three factors do not explain everything, for it must be admitted that it is sometimes a certain intuition, believed to have its source in the Spirit, that has guided the church in its choices.

The different literary genres each have their own history

1. Paul's Letters

   Paul's name appears on 13 letters written over a period of 50 years. It is not known whether copies of the letters were kept by the author or the recipient of the letters. We know that the communities exchanged these letters (Col 4:16). Some letters were modified after they were sent. It is possible that after the publication of the Acts of the Apostles and after Paul had become a well-known figure, a systematic collection of the letters was made. Biblical scholars attribute this collection work to certain figures like Onesimus (Phlm 10) or Timothy, or to a Pauline school of writers; this work must have continued after the first post-Pauline generation. Although some writers such as Ignatius of Antioch and the authors of 1 Clement and 2 Peter display knowledge of several of Paul's letters, it is only with Polycarp (70 - 155) and Marcion (100 - 160) that there is clear evidence of a large collection of these letters. The latter accepts ten letters, excluding the pastorals. At the end of the second century, 13 letters were accepted, the fourteenth (to the Hebrews) appearing only in the list of the Eastern Church, and finally appearing in the Latin list in the fourth century.

2. The Gospels

   The four gospels were composed over a period of time that stretches from 65 to 100. For Paul, no matter who proclaims it, there is only one gospel (Gal 1:8-9; 1 Cor 15:11). Thus, Mark's gospel, the first written according to biblical scholars, uses the word gospel in the singular, assuming that there are no other versions: "The beginning of the gospel of Jesus Christ the Son of God" (Mk 1:1). When the author of the gospel according to Matthew wrote a few decades later integrating two major sources, the gospel of Mark and a document that biblical scholars call "Q", he assumed to propose a new version of the same gospel, while eliminating the need to go back to the two sources he had used. In the introduction to his gospel, Luke mentions being aware of several previous accounts, but he nevertheless takes the initiative to write an ordered account himself so that his reader, represented by Theophilus, can know the truth more effectively. Finally, the fact that John's letters do not mention Mark, Matthew, or Luke, while referring to the "message heard" (1 Jn 1:5) suggests that the Johannine community knew only the fourth gospel. Bishop Papias (c. 125) knew several gospels, but before 150 there is no example of a Christian community offering more than one gospel for public reading.

   The habit of a Christian community to refer to only one gospel had perverse effects. Among Christians of Jewish origin, some preferred their own composition, but the majority opted for the gospel according to Matthew, which insisted on the importance of every little point of the Law, in a polemical reaction against Christians of pagan origin who based themselves on other writings to distance themselves from the Law. As for the Gospel of John, it became the privileged reference of the Gnostic movement to reject the world, based on some of its affirmations. It was not until after the year 150 that the reading of the four gospels became a common practice of the "great church". In an effort to compromise, Tatian (120 - 180) undertook to compose an account (Diatessaron) that harmonized the four gospels; while this account was accepted and authoritative for centuries in the Syriac churches, it was rejected by the Greek and Latin churches. It took Irenaeus of Lyon (130 - 202) and Origen (184 - 253) to make it clear that God wanted four gospels for his church.

   Marcion (100-160) played a role in the constitution of the canon of NT writings. The son of a bishop and a brilliant theologian, he arrived in Rome around 140 proclaiming that the creator of whom the Old Testament speaks is only a demiurge and rejecting all Jewish heritage. This led to his excommunication and the creation of his own church, which survived for three centuries. In his effort to denigrate the Law, he made extensive use of the letters of Paul and chose a number of writings that could support his thesis: the Gospel of Luke (without the infancy narratives), the ten letters of Paul (without the apostolic letters). All this fueled the churches' determination to maintain the OT as the word of God for the Christian people. And the fact that Marcion proposed a truncated canon of Christian writings also led the churches to establish a broad gospel (four evangelists, not just Luke) and a broad group of letters (thirteen rather than ten). Such expansion probably played a role in the addition of the Acts of the Apostles, which featured Peter and Paul, and thus appeared to be the bridge between the gospels and Paul's letters. And the idea of favoring the Twelve probably contributed to the addition of 1 Peter and 1 John, so that by the year 200 we end up with about twenty works (4 gospels, 13 letters of Paul, Acts, 1 Peter, 1 John).

3. Completing the Collection

   The other works (Hebrews, Revelation, James, 2 and 3 John, Jude, 2 Peter) are cited between the 2nd and 4th centuries, but they are not accepted by all churches. It was finally in the 4th century that the Eastern and Western churches agreed on a corpus of 27 works. This is the result of an ecumenical work where Christians from the east and west began to visit each other, and thus experienced the catholicity of the church.