Perched in the middle of a Victorian dining room, and surrounded by antique Asian vases, the world's third oldest Bible is now on display in Washington, D.C.

The Codex Washingtonianus, located at the Smithsonian's Freer Gallery of Art, is so closely guarded that it rarely makes public appearances—until now. The codex plays a pivotal role in scholars' understanding of the New Testament's history and speaks to how early Christians saw the Gospels.

Curators recently put the priceless document on display in the Freer Gallery's Victorian Peacock Room, along with a second of four ancient manuscripts purchased by Detroit businessman Charles Lang Freer, the museum's founder. The two remaining manuscripts are too delicate or damaged to be put on display. The public can view the rare Bible and manuscript at the gallery until February 16, 2014, without charge.

The codex was transcribed in Egypt during the era of the Eastern Roman Empire, likely in the late fourth or early fifth century. It is written in Greek on parchment—processed leather scraped thin to form pages. The pages are sensitive to light and humidity, which is why the codex never leaves the museum and isn't exhibited very often.

Although it looks a little worse for the wear—the edges were burned in a long-ago fire and pores from the animal skin are still visible—it's an important part of biblical scholarship. (See also "Lost Faces of the Bible.")

"Ninety percent of our surviving [biblical] manuscripts are from the tenth century or later," said Michael Holmes, a biblical scholar at Bethel University in St. Paul, Minnesota. "So anything that comes from earlier is intrinsically valuable."

There are only two other complete texts of the Gospels—Matthew, Mark, Luke, and John—that are older, added Craig Evans, a biblical scholar at Acadia University in Nova Scotia. They are the Codex Vaticanus, which is held at the Vatican, and the Codex Sinaiticus, most of which is held at the British Library in London.

"They're both fourth century," said Evans. "Somewhere between 330 and 340." The Codex Washingtonianus is in rarefied company, he added.

All Shook Up

In addition to its rarity, the Washingtonianus is best known for an extra passage near the end of the Gospel of Mark that is attributed to Jesus and that doesn't appear in any other known biblical manuscript.

The part that caught the attention of the public in the early 1900s reads in translation: "And Christ replied to them, 'The term of years of Satan's power has been fulfilled, but other terrible things draw near.'"

That passage seemed to address the question of whether God or Satan was in charge, said Bethel University's Holmes.

At the time, news of the passage came amid rumblings that the King James Version wasn't sufficiently representative of the earliest iteration of the Bible, said Evans. Conservative Christians were unhappy about that, he added.

So the publication of the Codex Washingtonianus, with its additional passage attributed to Jesus, caused more consternation because it was another challenge to the Bible people knew, Evans said.

It's not so much a problem now, he said. But at the time, it shook up a lot of people. (Read "The Judas Gospel" in National Geographic magazine.)

Literary License?

The additional passage, referred to as the Freer logion, was probably an oral saying that somehow made its way into the Gospels, said Holmes.

"There's no religious tradition that uses it as part of Scripture," he said. "It's almost like a margin comment that somebody wrote down because they heard it and wanted to remember it, and a scribe worked it in later."

That's possible because the Codex Washingtonianus was likely copied from multiple sources.

Four different textual styles are represented in the document, Holmes explained. "[It] looks like a composite of fragmentary Bibles."

It would be like picking up a modern-day Bible and reading one part of the Gospels from the King James Version, then another part clipped from the Revised Standard Version, a third part from the New International Version, and a fourth part from the New English Bible.

At the time the Washingtonianus was written down, Christianity was a recently legalized religion: Emperor Constantine had passed a law—the Edict of Toleration—legalizing Christianity in 313. But before that, Roman authorities persecuted Christian churches and their congregations, said Holmes.

Book burnings were part of the Roman campaign, said Lee Glazer, associate curator of American art at the Freer Gallery, whose jurisdiction includes the codex.

The two scribes who transcribed the Washingtonianus likely copied from fragments of several Bibles—remnants perhaps from an attack on a Christian church, said Holmes.

Mysterious and Beautiful

When Charles Freer bought the Codex Washingtonianus from an antiquities dealer in Egypt in 1906, he didn't know how important the pages would become, said the Smithsonian's Glazer.

View Images The Smithsonian's Freer Gallery of Art in Washington, D.C., holds a rare, ancient Bible, shown above, called the Codex Washingtonianus, that is on display. PHOTOGRAPH BY NATIONAL GEOGRAPHIC MULTIMEDIA

"He wasn't particularly religious, and he wasn't really attracted to them as sacred texts," she said. Glazer thinks Freer purchased the codex partly because he found it mysterious and beautiful.

Freer was a known collector of Asian art, and in 1906, his pieces were officially accepted into the Smithsonian. The collection didn't physically move to Washington, D.C., until after his death in 1919.

"Once he knew [his] collection was going to a national museum, he had a desire to add older objects to the collection," Glazer said.

"This was part of that quest to seek out antiquities and things that he hadn't been terribly interested in up to that point."

After Freer brought the manuscripts back to his home in Detroit, Michigan, he would occasionally display them in his dining room—which was actually another piece of art he had purchased in London.

The dining room, called the Peacock Room, had been redecorated by artist James Whistler in 1876 and 1877. Freer bought it in 1904 and had it shipped to America.

Freer believed that art should be enjoyed for its own sake, said Glazer, so he would display pieces from different time periods and genres together.

The way the Peacock Room is currently displayed in the Smithsonian gallery mirrors how Freer displayed it in his home in 1908, said Glazer, complete with Asian ceramics.

Glazer hoped that by seeing the Washingtonianus in the former dining room, people would get a better sense of how Freer viewed his own collection.