How did the Church decide which books to include in the New Testament? When was the decision made? By whom? The surviving evidence unfortunately does not provide answers in the detail we would like, but it does document a number of the developments that eventually produced the New Testament as we know it.
At a very early stage (by the end of the first century) several churches had collected some of Paul’s letters. Clement, traditionally regarded as the third bishop of Rome, although this is uncertain, wrote a letter from Rome to the church in Corinth in which he exhorts them to read part of Paul’s first letter to the Corinthians (1 Clement 47:1–3).a It thus appears that the church at Rome possessed a copy of Paul’s letter less than half a century after he wrote it. The author of 2 Peter also seems to know of a collection of Paul’s letters (2 Peter 3:15–16).
The second-century bishop of Antioch, Ignatius, wrote letters to seven churches while he was en route to Rome, where he suffered martyrdom. Ignatius frequently attempts his own elaboration of Paul’s ideas in these letters, and when he tells the Ephesians that Paul mentions them “in every letter” (Letter to the Ephesians 12:2), Ignatius shows that he knows at least several of Paul’s letters.