The questions “Who wrote most of the New Testament?” and “Who wrote most of the books of the New Testament?” are different questions with different answers. By number of books, Paul is at the top; by volume, Luke is the winner.
The apostle Paul wrote the most books of the New Testament—13 total out of 27:
• 1 and 2 Corinthians
• 1 and 2 Thessalonians
• 1 and 2 Timothy
Paul clearly identifies himself as the author of each “book” that he wrote. Actually, all of his writings are epistles (letters) written to individuals or churches to instruct them in the faith.
1 Timothy 1:1–2 is a typical greeting:
Paul, an apostle of Christ Jesus by the command of God our Savior and of Christ Jesus our hope,
To Timothy my true son in the faith:
Grace, mercy and peace from God the Father and Christ Jesus our Lord.
Modern critical scholarship has taken great pains to try to dispute certain letters as inauthentic because they contain teachings that do not fit their preconceived notions of what Paul would have said or because of slight differences in style or vocabulary within certain letters. (Modern critical scholarship only accepts Romans, Galatians, Philippians, 1 Thessalonians, and Philemon as indisputably written by Paul.) However, none of these challenges are convincing, and a good New Testament Introduction like the one by Carson and Moo will address these issues in-depth and provide good evidence for Pauline authorship of all 13 letters attributed to him.
At one time, many felt that Paul had also written Hebrews. However, the author does not identify himself as Paul. Likewise, the author does not count himself as an eyewitness to Jesus as Paul did. In Hebrews 2:3, the author says, “This salvation, which was first announced by the Lord, was confirmed to us by those who heard him.” The author of Hebrews received the gospel from someone else who had received it firsthand. Paul makes it clear that he received the gospel directly from Jesus: “I want you to know, brothers and sisters, that the gospel I preached is not of human origin. I did not receive it from any man, nor was I taught it; rather, I received it by revelation from Jesus Christ” (Galatians 1:11–12). Someone other than Paul must have written Hebrews, but that person did not identify himself. The content is clearly consistent with the rest of New Testament teaching so, in this case, identifying the human author is not critical.
By volume, Luke is the writer who wrote the largest part of the New Testament. The Gospel According to Luke and the Acts of the Apostles are two of the longest books; together, they make up about 27.5 percent of the New Testament. Luke and Acts are really volumes 1 and 2 of the same work, which scholars often refer to as Luke-Acts. The introductions of each work explain that Luke is writing for a man named Theophilus who wants to know the factual basis of his faith. Luke carefully investigated the facts concerning Jesus’ life, consulting documents and interviewing eyewitnesses (see Luke 1:1–3).
Luke was also a traveling companion of Paul and an eyewitness himself to many of the events reported in Acts.
After Luke and Paul, John is the most prolific New Testament writer, having written the Gospel According to John, the epistles 1, 2, and 3 John, and Revelation.
The rest of the books, with the exception of the anonymous Hebrews, are named for their authors:
• The Gospel According to Matthew — Matthew, the disciple of Jesus
• The Gospel According to Mark — Church tradition says that Mark served as a secretary for Peter and the Gospel of Mark is based on Peter’s preaching. Mark had also worked with Paul as a missionary.
• James — James, the brother of Jesus
• 1 and 2 Peter — Peter, the disciple and apostle
• Jude — Jude (Judas), the brother of Jesus
While the human author and provenance are important, more important is that the books of the New Testament were inspired by the Holy Spirit. We can speak of the human author, but we must remember that all of the books of the Bible have a single, divine Author.