The Bible has no single author. It is a collection of texts composed and edited by many different writers over several centuries, with traditional attributions — Moses for the Pentateuch, the Apostles for much of the New Testament — now largely rejected by mainstream scholarship in favour of a picture involving multiple anonymous authors, editors and scribal communities. Both views are set out below.
| Section of the Bible | Traditional Attribution | Scholarly Consensus | Dates (approximate) |
|---|---|---|---|
| Pentateuch (Torah) | Moses | Multiple sources (J, E, D, P) compiled by editors | 10th to 8th century BCE and later |
| Historical and Prophetic books | Named prophets and figures | Anonymous authors; later edited | Varies widely |
| Paul’s letters | Paul of Tarsus | Largely accepted; some letters disputed | From around the year 50 |
| Gospels and Acts | Matthew, Mark, Luke, John | Anonymous; titles added by scribes later | Within the range 50 to 150 |
| Later New Testament books | Various Apostles | Many considered pseudonymous | Within the range 50 to 150 |
The Traditional View: Named Authors Across the Testaments
For most of Jewish and Christian history, the authorship of the Bible’s major sections was understood to be straightforward. The five books that open the Hebrew Bible — Genesis, Exodus, Leviticus, Numbers and Deuteronomy, collectively the Pentateuch or Torah — were attributed to Moses, who according to tradition composed them in approximately the 14th century BCE. This attribution rested partly on passages within the books themselves that describe Moses writing, and partly on the authority of later biblical texts referring to the “law of Moses.”
The books of the prophets were understood to have been written by the prophets whose names they bear: Isaiah wrote Isaiah, Jeremiah wrote Jeremiah, and so forth. The Psalms were largely attributed to King David, the book of Proverbs to Solomon, and similar named figures were associated with other texts throughout the Hebrew Bible. These attributions gave the texts divine sanction: if Moses had received the law directly from God, then the books he wrote carried unique authority.
In the New Testament, tradition similarly tied each book to a named Apostle or close companion of Jesus. Matthew and John were understood to be Apostles writing from personal memory. Mark was said to have recorded the testimony of Peter, and Luke to have been a physician travelling with Paul. The letters attributed to Peter, James and John were understood to come from those figures directly. This framework made the 27-book collection a unified apostolic witness to the life and teaching of Jesus.
These traditional attributions still carry weight for many practising Jews and Christians today, and some conservative scholars continue to defend versions of them. They form an important part of how many people across centuries have understood their scriptures, and they cannot be set aside without engaging seriously with the reasons those traditions developed.
The Documentary Hypothesis: Four Sources Behind the Pentateuch
Scholars began to notice features within the Pentateuch that sat uneasily with single authorship: two distinct creation accounts in Genesis, different names used for God in different passages, contradictions in narrative detail and marked differences in style and vocabulary. These observations accumulated into what became known as source criticism.
The classic statement of this approach is the Documentary Hypothesis, whose most influential formulation was published by Julius Wellhausen in 1878. The hypothesis holds that the Pentateuch’s narrative is woven from four distinct source documents, each with its own theological concerns, vocabulary and historical background. These sources are referred to by the letters J, E, D and P.
The J source uses the divine name Yahweh from the outset and tends toward vivid, earthy storytelling. Source critics dated it to about the 10th century BCE, placing its composition in the early monarchy period. The E source uses the divine name Elohim and is dated to about the 9th century BCE; it is generally thought to originate in the northern kingdom of Israel. The D source underlies the book of Deuteronomy and shares distinctive legal and theological language with reforms associated with the Judean monarchy; its core is dated to the 8th century BCE. The P source emphasises ritual, genealogy and the holiness code; Wellhausen dated P to the period of the Babylonian exile or later.
The hypothesis proposes that later editors wove these sources together into the text now read as the Pentateuch. This would explain why the same story sometimes appears twice with different emphases, why God is called by different names in adjacent passages and why legal codes within the text sometimes overlap or contradict one another.
The Documentary Hypothesis in its classical Wellhausen form has been refined and challenged by subsequent scholarship. Some scholars have proposed fewer sources, others more; some question whether J and E can be cleanly separated at all. Nevertheless, the broad conclusion that the Pentateuch reflects multiple authorial traditions composed and compiled over several centuries remains the working assumption of most mainstream academic biblical scholarship. The traditional attribution of the whole to Moses writing in the 14th century BCE is not supported by the textual evidence as most scholars read it. Readers interested in the Bible’s historical reliability more broadly can explore that question at is-the-bible-historically-accurate.
The New Testament: Paul First, Gospels Later
The 27 books of the New Testament were written anywhere from the year 50 to the year 150, meaning that composition stretched across roughly a century. This chronological range matters, because it places some books well outside the lifetime of the people whose names they bear.
The oldest surviving Christian writings are not the Gospels but Paul’s letters. The earliest of these is most probably 1 Thessalonians, composed around the year 50, making it the oldest text in the New Testament by the reckoning of most scholars. Paul’s surviving letters constitute direct, first-person testimony from a figure whose historical existence is broadly accepted across scholarship. Even here, however, some of the letters attributed to Paul in the New Testament are widely considered by scholars to be pseudonymous, written by later authors in Paul’s name. Pseudonymous authorship was a common and accepted literary convention in the ancient world, so its presence does not necessarily imply deception by ancient standards, though it does complicate questions of attribution by modern ones.
The four Gospels were composed later than Paul’s letters. The titles attached to them — “According to Matthew,” “According to Mark” and so on — were not placed there by their authors. The titles of most New Testament books were not put there by their authors but added later by Christian scribes as the texts began to circulate and needed to be distinguished from one another. The original manuscripts appear to have been anonymous. This does not by itself settle questions of who wrote them, but it does mean that the traditional names cannot be taken as the authors’ own claims.
Whether the gap between the events described and the dates of composition affects the reliability of the Gospels is a question that different scholars and traditions answer differently, but the chronological distance itself is not seriously disputed. Those curious about how the Jesus story developed over time can find further context at origins-of-the-jesus-story.
How the Canon Was Formed
The idea that the Bible is a single, fixed book can obscure the fact that deciding which texts belonged in it was a prolonged and sometimes contentious process. The collection of authoritative texts we now call the Bible is the result of decisions made by communities and leaders across several centuries, not a process with one clear moment of conclusion.
In early Christianity, the situation was considerably fluid. Different communities used different texts, and there were significant disputes about which writings were genuinely apostolic and authoritative. Marcion, who died around 160, offers a striking example of how contested these boundaries were: he accepted only Luke and ten letters of Paul as scripture, rejecting the Jewish scriptures entirely. His position was condemned as heretical by other Christian leaders, but the controversy he generated helped push the broader church toward defining its own canon more carefully.
The first surviving list of exactly the 27 books now found in the New Testament was recorded in an Easter letter written by Bishop Athanasius of Alexandria in 367. Athanasius’s list matches the New Testament that most Christians use today, but reaching agreement across the whole church took longer still, and some books remained disputed in various regions for centuries after that letter was written.
The process of canon formation illustrates that the Bible as a collected volume reflects decisions made by human communities responding to theological and political pressures, not a self-evident or pre-packaged collection. What went in and what stayed out was genuinely debated. For a broader look at how modern readers might approach the biblical texts, have-you-read-the-bible-not-a-defence offers a useful perspective.
Why Catholic and Protestant Bibles Have Different Numbers of Books
A practical consequence of the canon-formation process is that not all Christian traditions ended up with the same Bible. The Catholic Bible contains 73 books in total, while the Protestant Bible contains 66. The difference lies entirely in the Old Testament: Catholic Bibles have 46 books there, while Protestant Bibles have 39.
The 7 additional books found in Catholic and Eastern Orthodox Old Testaments include texts such as Tobit, Judith, 1 and 2 Maccabees, Wisdom of Solomon, Sirach and Baruch, along with additions to Esther and Daniel. These are called the Deuterocanonical books by Catholics, who regard them as fully scriptural, and the Apocrypha by most Protestants, who typically regard them as edifying but not on the same level as the rest of scripture.
The divergence traces to which version of the Jewish scriptures was used as the basis for the Old Testament. The Greek translation known as the Septuagint, widely used in the early church, included these additional texts. Protestant Reformers returned to the Hebrew texts as their primary source and found that the Jewish canon did not include those books; most Protestant traditions consequently removed them from the authoritative canon, though some Protestant Bibles still print them separately.
The New Testament books, by contrast, are the same 27 books across virtually all Christian traditions, reflecting the eventual consensus that Athanasius’s list of 367 helped to stabilise.
Frequently Asked Questions
Did Moses write the first five books of the Bible?
Tradition attributed the Pentateuch to Moses, writing in approximately the 14th century BCE. Mainstream biblical scholarship, however, identifies multiple source documents woven together by later editors, with the sources themselves dated to between the 10th and 8th centuries BCE, and the Priestly source dated by Wellhausen to the exile period or later. The textual evidence — differing divine names, repeated narratives and varying styles — makes single authorship in Moses’s lifetime very difficult to sustain on scholarly grounds.
Who wrote the Gospels?
The Gospels were originally anonymous. The titles attributing them to Matthew, Mark, Luke and John were added later by Christian scribes, not by the authors themselves. The New Testament’s books were written anywhere from the year 50 to the year 150, and the Gospels are generally placed toward the later part of that range. Whether their authors were the Apostles named in the titles is debated; many scholars regard the traditional attributions as uncertain.
What is the oldest book in the New Testament?
The oldest text in the New Testament is most probably 1 Thessalonians, one of Paul’s letters, composed around the year 50. Paul’s letters predate the Gospels and are the earliest surviving Christian writings, making them a particularly significant source for early Christian belief.
When was the New Testament canon finalised?
The first surviving list of exactly the 27 books now in the New Testament appears in the Easter letter of Bishop Athanasius of Alexandria in 367. Full agreement across all Christian communities came later still, as some books remained disputed in different regions for centuries after that letter was written.
Why does the Catholic Bible have more books than the Protestant Bible?
The Catholic Bible has 73 books and the Protestant Bible has 66. The difference is in the Old Testament: Catholic Bibles contain 46 books there, Protestant Bibles 39. The extra 7 books, called Deuterocanonical by Catholics, were part of the Greek Septuagint used in the early church but were absent from the Hebrew Jewish canon that Protestant Reformers used as their primary reference.
What is the Documentary Hypothesis?
The Documentary Hypothesis is a scholarly theory, classically formulated by Julius Wellhausen in 1878, proposing that the Pentateuch was compiled from four distinct source documents: J, dated to around the 10th century BCE; E, dated to around the 9th century BCE; D, with a core dated to the 8th century BCE; and P, dated by Wellhausen to the exile period or later. Later editors combined these sources into the text now read as a continuous narrative.
Summary
The Bible was not written by one person, in one period or with one editorial hand. The traditional picture — Moses composing the Torah in the 14th century BCE, Apostles recording the life of Jesus shortly after his death — reflects the beliefs of the communities that treasured these texts and continues to hold religious significance for many people. The scholarly picture, built on close reading of the texts themselves, presents something considerably more layered: multiple anonymous source documents woven into the Pentateuch over several centuries, New Testament books written anywhere from the year 50 to the year 150, titles added to those books by scribes rather than authors, and a canon whose boundaries were actively contested for centuries.
The oldest Christian writings are Paul’s letters, with 1 Thessalonians dated to around the year 50. The first surviving list matching the modern 27-book New Testament was not written until 367, in a letter by Bishop Athanasius of Alexandria. The Old Testament differs between Catholic and Protestant traditions to this day, with 46 books in the Catholic canon and 39 in the Protestant, reflecting different decisions about which ancient collection of Jewish scriptures to treat as foundational. These facts do not resolve questions about the Bible’s meaning or authority, but they do clarify how the collection came to be what it is.
Sources
- Christine Hayes, "Critical Approaches to the Bible", Open Yale Courses, RLST 145, Lecture 5 (2006). oyc.yale.edu.
- Dale B. Martin, "Introduction: Why Study the New Testament?", Open Yale Courses, RLST 152, Lecture 1 (2009). oyc.yale.edu.
- Dale B. Martin, "From Stories to Canon", Open Yale Courses, RLST 152, Lecture 2 (2009). oyc.yale.edu.
- John D. Meade, "Why the Catholic Bible Has More Books than the Protestant Bible", Text & Canon Institute (7 November 2021). textandcanon.org.