Students of the Bible are so familiar with the name "New Testament" that often they do not pause to consider its original meaning and true significance. It implies a definite relation to the Old Testament, but an equally definite distinction from it. Both are "testaments," but one contains the Law, the other the Gospel; one records prophecy, and the other its fulfillment; one, in short, is called Old, and the other New.
It may well be asked why our Bible is divided into two volumes entitled, in effect, "The Old Will" and "The New Will"—for in the early centuries "testament" usually meant "will," even as it does today. Our question is partially answered when we realize that the word diatheke— which seems always to have meant "will" or "testament" in classical Greek—is used in the Bible to mean either "testament" or "covenant."
The Old Testament contains various significant references to covenants represented as made by God Himself either with individuals or with the people as a whole. Following the flood, God is said to have made a covenant with Noah, giving the symbol of the rainbow as "the token of the covenant"—a visible sign or guarantee that there would be no recurrence of such a universal calamity (Genesis 9:12). With Abraham began the era of ceremonial law, the covenant mentioned in this connection being considered as sealed by the rite of circumcision (Genesis 17: 10f.). In Moses' day we read of another covenant which God made with the people (cf. Exodus 19:5), the seal of the covenant in this instance being the commandments of the moral law, while a portion of the law received by Moses is explicitly described as "the book of the covenant" (Exodus 24:7). It remained for Jeremiah, however, to conceive of a new and higher type of covenant, which would be both inward and spiritual. "Behold, the days come, saith the Lord, that I will make a new covenant with the house of Israel. ... I will put my law in their inward parts, and write it in their hearts" (Jeremiah 31:31-33). In short, the Old Testament, being largely a record of God's covenants with men, is well thought of as "the Old Covenant," while it also foretells the "New Covenant" or New Testament of the Christian church.
