A piece of the Gospel of Mark believe to have been written before the year 90 - making it the oldest known gospel - is about to be published, according to Live Science.

The gospel was written on papyrus which was then used to make a mask for a mummy. Pharaohs wore golden masks, but ordinary citizens would wear masks made of papyrus or linen, paint and glue - a paper mâche mask. Since these supplies were still expensive, papyrus that had been written on often got reused, according to Live Science.

Scientists are able to unglue the paper without destroying the writing on it.

"We're recovering ancient documents from the first, second and third centuries," said Craig Evans, a professor of New Testament studies at Acadia Divinity College in Wolfville, Nova Scotia, according to Live Science. "Not just Christian documents, not just biblical documents, but classical Greek texts, business papers, various mundane papers, personal letters."

Even copies of Homer's stories have been peeled from masks.

By using dates on other papers on the mask, Evans said that his team was able to determine the date of the gospel.

Some scholars think that this method is not worth the destruction of mummy masks, but Evans told Live Science that the pieces they are undoing are often just cartonnage - the material used in mummification of bodies.

"We're not talking about the destruction of any museum-quality piece," Evans told Live Science.