The Old Testament is a Christian term for the religious writings of ancient Israel held sacred by both Judaism and Christianity. The number of these writings varies markedly between denominations, Protestants accepting only the Hebrew Bible's canon but dividing it into 39 books, while Catholics, the Eastern Orthodox, Coptic and Ethiopian churches recognise a considerably larger collection.

The books can be broadly divided into the Pentateuch, which tells how God selected Israel to be his chosen people, the history books telling the history of the Israelites from their Conquest of Canaan to their defeat and exile in Babylon, the poetic and "wisdom" books dealing, in various forms, with questions of good and evil in the world, and the books of the biblical prophets, warning of the consequences of turning away from God. For the Israelites who were its original authors and readers these books told of their own unique relationship with God and their relationship with Proselytes, but the over-arching Messianic nature of Christianity has led Christians from the very beginning of the faith to see the Old Testament as a preparation for the New Covenant and New Testament.