Who Decided Which Books to Include in the Bible?

Luther had issues with the book of James, which emphasized the role of "works" alongside faith, so he stuck James and Hebrews in the back of the Bible alongside Jude and Revelation, which he also thought were questionable. Combs says that in Luther's original Bible, those four books don't even appear in the table of contents.

Eusebius was a Christian historian writing in the early 300s who provided one of the early lists of which books were considered legit and which were borderline bogus.

Eusebius broke his list down into different categories: recognized, disputed, spurious and heretical. Among the "recognized" were the four gospels (Matthew, Mark, Luke and John), Acts and Paul's epistles. Under "disputed," Eusebius included James and Jude — the same books Luther didn't like — plus a few others that are now considered canon, like 2 Peter, 2 John and 3 John.

When Eusebius turns to the "spurious" and "heretical" categories, we get a glimpse into just how many other texts were in circulation in the second and third century C.E. Have you ever heard of the Apocalypse of Peter, the Epistle of Barnabas or the Gospel of Thomas? Combs says that there were hundreds of texts similar to those found in the New Testament and Old Testament that didn't make it into the canon.

Why did some books make the cut and not others? Combs cites three criteria used by early church leaders. The first was authorship, whether it was believed to have been written by an apostle, by Paul or by someone close to them. Mark, for example, wasn't an apostle, but was an interpreter for Peter. The second criterium was antiquity, with older texts taking priority over newer ones. And the third was orthodoxy, or how well the text conformed with current Christian teaching.

"That last reason is so interesting, of course, because 'current Christian teaching' changed over hundreds of years," says Combs.

While it's not true to say that a single church council ruled on which books to include in the canon, it's fair to say that over those first few centuries of theological debate, the winners got to decide which books would stay and which had to go.

It's important to mention that not all Christian denominations consider the same books to be canon. Most Protestant Bibles have 66 books, 39 in the Old Testament and 27 in the New Testament. The Roman Catholic Bible has 73 books including the seven known as the Apocrypha. And the Ethiopian Orthodox Church includes 81 total books in its Bible, including pseudepigrapha like 1 Enoch and Jubilees.

The word "apocrypha" comes from the Greek for "hidden" or "secret." It's a little confusing, because the word apocrypha is used in a couple of different ways when talking about books outside of the standard biblical canon.

First, there's the category of "New Testament Apocrypha" which includes a long list of non-canonical texts written mostly in the second century C.E. and beyond that pertain to Jesus and his apostles. As Combs says, there are hundreds of these texts and we don't have written specimens for all of them.

Then there's a subset of Old Testament books that are included in the Roman Catholic Bible. These seven books, including Tobit, Judith and 1 & 2 Maccabees, are published between the Old and New Testaments in the Catholic Bible and called "the Apocrypha" or sometimes the "Deuterocanon" which means "second canon."

And then there's a third category called "pseudepigrapha" from the Greek for "false author." This list includes more than 50 texts written between 200 B.C.E. and 200 C.E. by both Jewish and Christian writers expanding on stories and characters from the Old Testament. Notable Old Testament pseudepigrapha include 1 Enoch, Jubilees and the Treatise of Shem.

Many of the New Testament texts familiar to Christians today were being used authoritatively already in the second century, but different congregations preferred some texts over others and included some texts that don't appear in the New Testament. Here are a few:

The Gospel of Peter: Only a fragment of this text was recovered in 1886 in Egypt, but it includes the only narrative account of the resurrected Jesus leaving his tomb. According to Peter's version, two giant angels descended to the tomb and escorted the resurrected Jesus out, who was also suddenly gigantic. But the oddest note was that the three figures were followed by a floating cross that could talk.

"And they heard a voice from the heavens, saying, 'Thou hast preached to them that sleep.' And a response was heard from the cross, 'Yea.'"

The Gospel of Mary: Combs says that some apocryphal texts reflected theological and doctrinal debates going on within the early church, such as the role of women. In the Gospel of Mary (discovered in the late 19th century), Mary Magdalene is not only referred to as one of Jesus's disciples, but perhaps his favorite one. In this text, after Jesus is resurrected, he relays esoteric teachings to Mary, who then tells the other disciples. Peter asks why they should listen to a woman, to which another disciple Levi [Matthew] responds:

"If the Savior made her worthy, who are you then, for your part, to cast her aside? Surely the Savior knows her full well. That is why he has loved her more than us."

1 Enoch: Purportedly written by the ancient prophet Enoch before the time of Noah, this text was well-known to early Christians like third-century theologian Tertullian and quoted as authoritative scripture. The text is famous for its description of the "Watchers," fallen angels mentioned briefly in the Old Testament book of Genesis. These angels lusted after human women and came down to Earth to be with them, creating giant offspring. In 1 Enoch, these angels also introduce evil into the world in the form of weapons, magic and sexy makeup.