As I have argued at length in various places, the role of the apostles is central to the establishment of the New Testament canon. They were the authorized spokesmen for Jesus, so when they spoke, he spoke. Consequently, when they wrote their teachings down, they would have been recognized as an authoritative source for the life of the church.
But this raises an obvious question: What about the authors of the New Testament that were not apostles? Does this negate the authority of those books? In particular, we might think of authors like Mark and Luke who penned two of our Gospels. Are their Gospels less authoritative because they weren’t apostles?
Not at all. An apostle does not have to “hold the pen” (so to speak) in order for a book to have apostolic authority. Rather a book has apostolic authority if we have reasons to think the contents come directly from an apostle.
In the case of Mark and Luke, it’s quite plain that they are directly passing along apostolic teaching. It was widely understood in the early church that Mark was the disciple of Peter and that his Gospel was basically Peter’s own remembrances of Jesus and his teachings. And Luke positions himself as a direct student of the apostles in his prologue where he says he got his material from those who were “eyewitnesses and minsters of the word” (Luke 1:2). That is, apostles.
It was so clear that Mark and Luke were effectively apostolic Gospels that Justin Martryr was able to call all four Gospels “memoirs of the apostles” despite the fact that two of them were not technically apostles.
But about James and Jude? In their case, there are actually reasons to think they may have been regarded as apostles in the early church.
Paul implies that James might have been considered an apostle when he refers to “James and Cephas (Peter), and John” as “pillars” of the church (Gal 2:9)—which is incidentally the same order the books from these three individuals appear in the New Testament—and also mentions James alongside “the other apostles” (Gal 1:19).
The possibility that James might have been regarded as an apostle finds additional support in the fact that Paul mentions Jesus made a special resurrection appearance not only to the twelve but also to James (1 Cor 15:7).
We see something similar in the case of Jude. When defending his right to take a wife on missionary journeys, Paul appeals to the fact that this right also belongs to “the other apostles and the brothers of the Lord and Cephas” (1 Cor 9:5). This indicates that multiple brothers of the Lord were known to be travelling missionaries.
While Paul might have included James in this group, that seems unlikely given that James is always associated with a singular location, namely Jerusalem. But these travelling brothers would no doubt have included Jude, along with other named brothers of Jesus such as Joses and Simon (Mark 6:3).
It should not be missed that Paul’s language seems to imply that these brothers of the Lord might have had some sort of apostolic status. While it might seem, at first glance, that the “brothers of the Lord” are a separate category besides apostles, the fact that they are listed between the “other apostles” and the apostle “Cephas” (Peter), is highly suggestive that they enjoyed the same authoritative status.
Lastly, there is the book of Hebrews whose authorship is anonymous. Some in the early church thought Paul was the author, and others did not. Regardless, the author of the letter clearly positions himself as an “apostolic man” when he indicates the Gospel message “was attested to us by those who heard, while God also bore witness by signs and wonders and various miracles and by gifts of the Holy Spirit” (Heb 2:3).
In other words, apostles.
In the end, it is fair to say that the entire 27-book corpus of the New Testament is apostolic. In some fashion, they all bear official apostolic testimony about Jesus and his message. Thus, they all bear the very authority of Jesus himself.