The editors of every version of the Bible have split the Bible into two parts: the Old Testament (Genesis–Malachi) and the New Testament (Matthew–Revelation). This major division is intentional, logical, and significant.
The Bible is split into two parts (Testaments) to indicate the two major salvific events and covenants in salvation history: (1) the salvation of God’s people from slavery to Egypt and the subsequent Sinai Covenant and (2) the salvation of God’s people from sin and Satan based on the New Covenant.
The 400-Year Silence
The first reason that the Bible is split into two parts is that there was a 400-year silence after Malachi, the last book of the Old Testament, was written. The book of Malachi was written around 430 BC.[1] From the time of Malachi to the arrival of Jesus and the writing of the Gospels and New Testament letters, roughly 400 years had passed. During those 400 years, the biblical canon (i.e., the Old Testament) was complete (see my article on that topic here) and God had not done another major work in salvation history.
Once Jesus arrived, however, it became evident that the next major stage in salvation history had begun. Thus, biblical editors chose to indicate that the collection of writings we now call the New Testament were written during this new part of salvation history by putting them together in their own section called ‘the New Testament.’ Jesus’ arrival and salvific work on the cross is the second (and primary) reason for dividing the biblical text into two major parts, and it is to this topic that we now turn.
The Two Major Covenants of Salvation History
The primary reason that the editors of all Bibles rightly split the Bible into two parts is because the Old Testament is primarily about God’s salvific work in and through the Sinai Covenant (called the Old Covenant in the book of Hebrews) and the New Testament is primarily about God’s salvific work in and through the New Covenant, which was ratified by Jesus’ blood at his death on the cross. Let’s take a brief look at each covenant and the relationship of the biblical books to each covenant.
The Sinai Covenant and the Old Testament
The Sinai Covenant is the first of two major covenants in the Bible. The Sinai Covenant (also called the Mosaic Covenant, the Old Covenant, or the Old Testament [‘Testament’ is another word for ‘Covenant’) is God’s covenant with the people of Israel after he freed them from Egyptian slavery. The stipulations of the covenant are given in Exodus 19:1–24:3 and the covenant is ratified with the blood of oxen thrown upon the altar and upon the people of Israel in Exodus 24:4–8. The Sinai covenant essentially says that (a) Yahweh will be Israel’s God (Yahweh is God’s personal name; click here for more information), (b) Israel will be Yahweh’s people, (c) Israel must obey God’s laws (d) so that Yahweh will constantly dwell with Israel and do good to Israel.
The biblical books Genesis–Malachi are in the part of the Bible called ‘The Old Testament’ because all of these books (a) were written by God’s people while under the Sinai Covenant (also called the Old Testament) and (b) are primarily about God and his people in relation to the Sinai Covenant. For example, although Genesis 1:1–Exodus 18:27 is about God’s creation of the universe and about God’s people prior to the ratification of the Sinai Covenant, it was written by Moses after the Sinai Covenant was ratified (for Moses as the author of the Pentateuch, see my article on authorship of the Bible here). The same is true for all 39 books of the Old Testament, with the possible exception of Job, whose author and dating are near impossible to tell.
Further, Exodus 19:1–Malachi 4:6 is primarily about God and his people in relation to the Sinai Covenant. This includes God’s blessings to his people when they are obedient to the covenant stipulations, God’s curses upon his people when they are not obedient to the covenant stipulations, the inability of the Sinai covenant to change people’s hearts and truly deal with sin, and the need for a new covenant (Jeremiah 31:31–34).
Thus, Genesis–Malachi are rightly called the Old Testament because each book was written by someone under the Sinai Covenant and the majority of the content is about God and his people in relation to the Sinai Covenant.
The New Covenant and the New Testament
The New Covenant is the second of two major covenants in the Bible. The New Covenant is the next major step in God’s salvation plan after the Sinai Covenant. The New Covenant is God’s covenant with his people that forgives their sin, changes their heart, gives each person the Holy Spirit, enables God’s people to obey Him in ways that were not possible under the Sinai Covenant, have victory over Satan, and much more (see Jeremiah 31:31–34 and Hebrews 8–10 for a concise explanation of the New Covenant).
The New Covenant was ratified by Jesus’ blood at his death on the cross, made clear at the Last Supper in Luke 22:20. Jesus’ blood is sprinkled on his people by the Holy Spirit through faith in Jesus (1 Pet 1:1–2), making those who repent of their sin and believe in Jesus as God’s people who are under the New Covenant. The New Covenant is better than the Sinai Covenant:
“But as it is, Christ has obtained a ministry that is as much more excellent than the old as the covenant he mediates is better, since it is enacted on better promises. For if that first covenant had been faultless, there would have been no occasion to look for a second.”
HEBREWS 8:6–7, emphasis added
The New Covenant also replaces the Sinai Covenant:
“In speaking of a new covenant, he makes the first one obsolete. And what is becoming obsolete and growing old is ready to vanish away.”
HEBREWS 8:13
The biblical books Matthew–Revelation are in the part of the Bible called ‘The New Covenant’ because all of these books (a) were written by God’s people while under the New Covenant and (b) are primarily about God, his Messiah Jesus, and God’s people in relation to the New Covenant. For example, the four Gospels were written by apostles or those close to the apostles about Jesus’ birth, life, death, resurrection, and ascension after Jesus’ ascension while the apostles were under the New Covenant. The rest of the New Testament was also written by those who were under the New Covenant (see my article on authorship and its importance here).
Further, all the books in the New Testament are directly related to the New Covenant. The Gospels are about Jesus and how he ushered in and ratified the New Covenant. The book of Acts is about how salvation in Jesus and the New Covenant is for all people, not just the Jews. And the NT letters Romans–Revelation are explaining the significance of Jesus, the significance of the New Covenant, and how to live in light of Jesus and the New Covenant.
Thus, Matthew–Revelation are rightly called the New Testament because each book was written by someone under the New Covenant and the majority of the content is about God, Jesus, and God’s people in relation to the New Covenant.
Summary and Concluding Comments
The editors of all Bibles have rightly divided the Bible into the Old Testament and the New Testament because each Testament is primarily about that particular Testament (or ‘Covenant’) and was written by authors under that particular Covenant. The Old Testament is primarily about the Sinai Covenant and the New Testament is primarily about the New Covenant.
Understanding the reason for the two Testaments also helps explain why Christians feel more comfortable in the New Testament; it is because we are people of the New Covenant. Pastors, priests, and elders preach primarily from the New Testament because it is more directly relevant, understandable, and applicable than much of the Old Testament. This does not mean Christians should ignore the Old Testament or never read/study the Old Testament—may it never be (μὴ γένοιτο)! But it does explain why we Christians are quickly drawn to the New Testament.
[1] Critical biblical scholars date the books of the Bible differently from confessional biblical scholars. For them, Malachi was not the last book of the Old Testament to be written. Many critical scholars date books such as Jeremiah, Daniel, 1–2 Chronicles, and Ezra-Nehemiah later than Malachi. Critical scholars date Malachi somewhere between 515–445 BC.