Why did it take so long to write the New Testament?

Answer 1

The first New Testament gospel to be written was that attributed to Mark, although it was originally anonymous and was only attributed to Mark later in the second century, as the Church Fathers were attempting to decide who probably wrote each of the gospels. Mark's Gospel was written approximately 70 CE, at the end of the First Roman-Jewish War. Whatever the actual reason, it is likely that the decision to write this Gospel was in some way related to the events of 70 CE.

Matthew's Gospel is believed to have been written sometime in the 80s of the first century, although Raymond E. Brown (An Introduction to the New Testament) cautions that a few years should be allowed either side of this decade. Luke's Gospel was written around the end of the century, and John's Gospel a few years later. As with Mark's Gospel, they were all written anonymously, and scholars say that the actual authors could not have been eyewitnesses to the events they wrote about. Matthew and Luke are known to have been based largely on Mark's Gospel, which provided everything the authors knew about the life and mission of Jesus. These authors could not have written earlier than 70 CE and probably did not receive copies of Mark until quite some time later.

John's Gospel was inspired by Luke, so of course its authorship had to await the completion of Luke's Gospel.

Acts of the Apostles can be shown to include material that could only have come from Antiquities of the Jews, published in 93 CE by the Jewish historian, Josephus.

Some of the Epistles attributed to Paul and the disciples of Jesus are known to have been written during the first half of the second century, but attributed to the apostles of the previous century in order to add weight to the messages they contained. The Pastorals (1 and 2 Timothy and Titus) were written to address issues that had arisen in the Christian Church during the second century, including the role of the newly designated office of bishop. The Epistles of John were written in response to a split in the Johannine community, that resulted in one group leaving to join the Christians allied to the 'centrist' tradition, while the other allied itself further to the Gnostic communities.