The Bible

The primary sacred text of Christianity is the Bible. Its name is derived from the Latin word biblia, which simply means "books." The Christian Bible is made of two parts: the Old Testament, which is almost identical to the Jewish Bible; and the New Testament, a collection of Christian writings that includes biographies of Jesus and the apostles, letters to new churches, and an apocalyptic work.

The names given to these two parts of the Bible are significant. The word testament means "covenant," so the notion of old and new testaments reflects the Christian perspective that the Church is the successor to Israel as God's chosen people. The Old Testament is viewed as foundational, authoritative, and relevant, and is read and cherished by Christians along with the New Testament. But it is also regarded as having been superceded and fulfilled by the new testament (covenant) God has made with the Church.

Catholic and Orthodox Bibles include the Apocrypha, while most Protestant Bibles do not. The Apocrypha ("hidden books") is a group of 13 Jewish books written between the Old Testament and the New Testament. Following the pattern of the Greek version of the Old Testament (the Septugint), the Apocrypha was included in all Christian Bibles until the Reformation. The reformers rejected the Apocrypha because it was sometimes used as a basis for certain Catholic doctrines and because the Jews have never included it in their biblical canon.

Some non-canonical early Christian texts were actually considered for inclusion in the New Testament, such as the Didache. Also known as the Doctrine of the Twelve Apostles, the Didache is a first-century text that exhorts its readers to choose the Way of Life over the Way of Death.

Another important set of early Christian texts has been rejected by mainstream Christians since almost the beginning: the Gnostic scriptures. Gnosticism was an early form of Christianity that early church fathers and church councils determined to be heretical. Sacred texts of the Gnostic Christians include sayings of Jesus, mystical teachings, apocalyptic works, and accounts of the apostles. Some of them may date to as early as the New Testament writings.