How was the Books of the Bible Canon Determined? Criteria for Being Included or Excluded
We currently working (Feburary 2026) on an article examining evidence for the identity of the human author of the Book of Hebrews. In that article, we’re including a chapter on why the identity of the author mattered with respect to the book being accepted into the Bible canon in the early church. That related article led to us writing this fuller treatment on all of the various criteria requirements for canonization.
Introduction
The Bible, or biblical canon, can be defined as a collection of sacred writings that is widely recognized and accepted as being divinely inspired, or as the Apostle Paul wrote, “God breathed” (Greek: theopneustos) in 2nd Timothy 3:16.
First, we note the existence of multiple Bible canons. For simplicity, we’ll confine this article to the top three that covers the overwhelming majority, those being the Protestant, Catholic, and Eastern Orthodox canons. For the New Testament (NT), all three canons contain the same 27 books. However, the number of Old Testament (OT) books vary in each canon. The Protestant canon, generally used by Baptists, Presbyterians, Lutherans, Evangelicals, Anglicans and others, follows the Hebrew Bible’s 39 books. The Roman Catholic OT canon however, included seven additional Deuterocanonical books. In addition, the Eastern Orthodox canons usually add 10-12 additional books (the Deuterocanonical books plus a few additional others).
In this article, we will focus primarily on the Protestant canon, since it contains the books that are common to all the canons.
Criteria for Being Included in the Old Testament Bible Canon
First, we note that there was no magical formula utilized to determine the OT canon. There was no single committee utilizing an official checklist of requirements for entry. Instead, it appears that the canon was determined by certain requirements developed as part of a grassroots movement over the centuries. Actually, it is more accurate to say that the canonicity of each book was “recognized” rather than “determined”, particularly amongst protestants. This differs somewhat between Protestants and Catholics. The Catholic would typically hold that the book was inspired because the church proclaimed it as such, while the protestant would say the book already possessed divine inspiration, and the church merely recognized it as such. We also note that in general, European Catholics tend to be more conservative on these and other issues, while some in America can even lean closer to the protestant position on this and other issues.
Thus, due to this bottoms-up recognition process, the formation of the canon spanned centuries, and was divided into three sections, the Law, the Prophets and the Writings. The first writings of Moses (the Torah), aka the Law, were completed in the 15th Century BC, and accepted about 1100 years later (~400 BC). Next, the Prophets (Nevi'im), consisting of Joshua, Judges, Samuel, Kings, Isaiah, Jeremiah, Ezekiel, and the Book of the Twelve (Minor Prophets) were accepted between 200 and 400 BC.. Finally, the Writings (Ketuvim), consisting of the Wisdom Books, Ruth, Esther, Daniel, Ezra-Nehemiah (originally one book), and Chronicles were accepted in the first two centuries AD. We now take a look at the major requirements or criteria for inclusion.
Divine Inspiration
The most basic and fundamental requirement was that the book being conceived by divine inspiration. That is to say that, God Himself inspired and guided the human author by the Holy Spirit, thus guaranteeing that the book is not merely of human origin, but an inerrant, trusted guide for teaching and transforming lives.
Authored by a Recognized Prophet
The first five books of Moses (the Law) were accepted because they were written by Moses, the greatest prophet of Israel (Dt 34:10-12). Each of the prophetical books books were written by a readily accepted prophet of Israel, such as Isaiah, Jeremiah, Ezekiel, or Daniel, that is one who was recognized to have prophetic authority. In most Jewish traditions, those prophetic gifts ceased around 400 BC at the end of Malachi’s ministry. Thus, later books such as those of the Apocrypha were excluded from the Hebrew canon. Despite this, the Roman Catholic Church canonized many of the non-authoritative books at the Council of Trent (1545 - 1563 AD) during their Counter-Reformation in Italy. The protestant church recognizes some historical benefits to these excluded volumes, but rejects their claim of inerrancy due to many contradictions and inconsistencies with established Scripture.
Antiquity / Language
Closely related to the previous requirement, the earlier books were written in Hebrew, while the rejected deuterocanonical works were written much later (often in Greek), and were thus rejected by the early Jews and by Protestants. Only the Roman Catholic Church and some Eastern Orthodox religions recognizes a number of these books.
Doctrinal Consistency
This requirement basically required that any new writings must be consistent with, and not contradict with any older and established revelatory truth. This test required any new writings to be in harmony with the Torah. Anything that contradicted with God’s Law given to Moses, God’s revealed character, or His covenant with Israel was immediately rejected. Later writings also had to be consistent with God’s character and teachings as revealed in other previously accepted books.
Established Acceptance, Usage and Preservation in Worship and Community
Various books gained recognition of authority with wide, sustained and consistent use in the Jewish synagogue services. Books of the Law, the Prophets and the Writings were increasingly kept and preserved in the Temple and synagogues, and regularly used in worship services. Thus with such wide usage, the books soon began to pass the test of time. As decades passed into centuries, the canon continued to form.
Final Form
By the first couple of centuries AD, Judaism recognized 22 to 24 books as being canonical. These books corresponded to the modern 39 books that we currently have in the Protestant Old Testament. Several of the original books were divided into two or more volumes. For example, the Book of the Kingdoms was divided into 1st and 2nd Kings (similar to the Chronicles), and the Book of the Twelve was divided into individual books. A few books were still being questioned, such as Ecclesiastes, Song of Songs, and Esther, but by the second century AD, the OT canon was basically set.
Criteria for Being Included in the New Testament Bible Canon
Unlike the disagreements amongst the various groups over the OT canon, the various groups (Protestant, Roman Catholic, Eastern Orthodox, etc) all recognize the same 27 books for the New Testament canon. Like the OT canon, however, the NT canon also developed gradually, in this case, over the first four centuries of Christianity AD. Again, like the OT canon, the canon was not “created by committee vote”, but gradually recognized the books that were already considered as “inspired by God”. The first known list of books containing the exact 27 books that we recognize today was drafted in 367 AD, and became known as the Athanasius' Easter letter. Shortly after, councils at Hippo in 393 and Carthage in 397 recognized the same list of 27 books. To re-iterate, the councils merely recognized and discerned what had already been widely received. We now take a look at the major requirements or criteria for inclusion in the NT canon. Many are very similar to those of the OT canon development.
Apostolic Authority / Divine Inspiration
Similar to the OT canon, the most basic and fundamental requirement was that the book had to be authored by an Apostle, or someone writing under the direction of an Apostle, such as Mark, a protégé of the Apostle Peter, and Luke, a close companion of the Apostle Paul. This guaranteed that the content was written by an first-century eyewitness (or someone aided by a first-century eyewitness), and that it was received by divine inspiration, or “God-breathed” (Greek Theopneustos) as stated by the Apostle Paul in 2nd Timothy 3:16. As with the OT books, God Himself inspired and guided the human author by the Holy Spirit, keeping him from errors in the original manuscripts. In addition, Apostolic authorship guaranteed a direction connection between the human author and Jesus Himself, thus guaranteeing the result that each book would be not only inerrant, but also like the books of the OT canon, a trusted guide for teaching and transforming lives. Divine Inspiration could be recognized by consistent and transformative impact of the text that contained a clear sense of divine authority. Thus, later Gnostic gospels such as the Gospel of Thomas were rejected.
Orthodoxy (Consistent with the “Rule of Faith”)
By the “Rule of Faith”, we mean the summary of apostolic teachings that circulated within the early churches (aka the faith that was once for all entrusted to God’s holy people (Jude 1:3). Much of these teachings were later included in the Creeds and Confessions. Teachings in the book obviously had to agree with the teachings of Jesus and the apostles. They also had to avoid theological and doctrinal contradictions, and be consistent with the major teachings of the OT (Hebrew Scripture). For example, any book that taught Gnosticism or other heresies as truth were immediately rejected.
Widespread Use Among the Various Churches
To meet this requirement, a book had to obtain and maintain, not only reliable authenticity, but also broad acceptance and regular use, both across the geographically diversified Christian communities, and consistently across time. This also required that the books had to be copied widely and consistently quoted by the early Church Fathers and other Christian leaders,. Books that were used only in certain regions were generally rejected.
How the Standards were Met
We now give an abbreviated historical timeline of the recognition of the NT books. The various letters of Paul were probably some of the first books to be widely recognized as inspired. The were in circulation amongst the churches by the mid to late first century as confirmed in Peter’s First Epistle that was written in the 60s AD (see 2nd Peter 3:15-16).
The four Gospels easily met the standards for canonicity. All were first century works and two by the well-known apostles Matthew and John. In addition, Luke, who also wrote Acts, was a close and frequent travelling companion with the Apostle Paul, while Mark wrote his gospel with aid from the Apostle Peter. Thus, the four Gospels were also circulating as four accounts of Jesus’s life and earthly ministry. There was one additional first-century work that came very close to being accepted. The First Epistle of Clement was written about 96 AD to resolve a dispute in the Corinthian church, and received much support from the early church fathers. Yet it was ultimately rejected when the author, Pope Clement I himself testified that he did not meet the strict criteria of apostolicity.
In the second and third centuries AD, the rise of several heresies forced the church to clarify between the heretical works and those that carried apostolic authority. Thus, we find a number of lists being formed. The first almost complete list was the Muratorian Fragment, dating back to the late 2nd Century. It contains a list of 22 of the 27 books. It was discovered in 1740 and was written in Latin, but possibly translated from Greek. In the late 4th century, councils such as Hippo (393) and Carthage (397) affirmed the 27-book canon that remains unchanged to this day.