Canon

Literally, a norm or measuring rod.

A term used in Christianity and Judaism to describe written works accepted as normative sacred scriptures.

The Canon of Scripture in Christianity refers to the set of books selected from among the books of the Hebrew Scriptures, the dozens of gospels, and many dozens of epistles, to form the Bible.

Some canons contain just the 39 books of the Hebrew Scriptures (Old Testament) and 27 books in the Christian Scriptures (New Testament). Other canons include the Apocrypha. Some liberal theologians have recommended that the canon be opened for additional writings, like the Gospel of Thomas; often regarded as the fifth gospel.