Old Testament vs. New Testament: How They're Different and How They Connect

The Old Testament and New Testament are two parts of the same Bible. The Old Testament lays the foundation by telling the story of creation, God's covenant with Israel, and the promise of a coming Messiah. The New Testament continues that story through the life, death, and resurrection of Jesus Christ, whom Christians believe fulfills those promises.

Let’s understand the difference between the two, their story, and whether you should read both or not. 

Quick Answer:

• The Old Testament (39 books) and the New Testament (27 books) tell one continuous story. 
• The Old Testament records creation, God's covenant with Israel, and the promise of a coming Messiah, while the New Testament reveals Jesus Christ as the fulfillment of those promises and introduces the new covenant.
• Both are written in different languages, time periods, and historical contexts, but are closely connected through shared themes, prophecies, and God's plan of redemption.
• Beginners should start with the Gospel of John or Mark, then read Acts and the rest of the New Testament before returning to the Old Testament for deeper context.

What Does "Testament" Actually Mean?

Testament means covenant, which is a formal agreement between God and his people.

That one word explains the entire structure of the Bible. The Old Testament is the account of God's covenant with the nation of Israel. The New Testament is the account of the new covenant that God makes with all of humanity through Jesus Christ.

So "Old" and "New" don't mean outdated and updated. They mean the first agreement and the fulfillment of it.

What Is the Old Testament?

The Old Testament is the first and much larger section of the Bible. It starts at the creation of the world and takes you through thousands of years of history, all the way to about 400 years before Jesus was born.

How Many Books Are There in the Old Testament?

It has 39 books, written mostly in Hebrew (with a few short passages in Aramaic, the language Jesus himself would later speak). These books were written by dozens of different people over roughly 1,000 years. 

Moses is traditionally credited with the first five books. David wrote many of the Psalms. The prophetic books, like Isaiah and Jeremiah, were written by the prophets themselves.

Book of the Old Testaments

For a short summary of what each book is about, check our complete guide on explaining bible books.

What's the Summary of the Old Testament?

The Old Testament is a story about a God who keeps reaching toward people who keep walking away and who never stops promising that something better is coming.

Here's the short summary:

1. Creation and Fall: God creates the world and humanity. Adam and Eve disobey him and are removed from Eden, and sin enters the story. (Genesis 1–3)
2. God's Covenant with Abraham: God makes a promise to Abraham: his descendants will become a great nation, and through them, the whole world will be blessed. (Genesis 12)
3. The Exodus and the Law: God rescues the Israelites from slavery in Egypt through Moses, then gives them the Law at Mount Sinai, a framework for how to live as his people. (Exodus through Deuteronomy)
4. The Kingdom of David: God establishes David as king. His son Solomon builds the Temple in Jerusalem. This is the high point, a brief, glorious season where things are as they should be. (1 Samuel 16 – 1 Kings 11)
5. Division, Decline, and Exile: The kingdom splits. The people repeatedly turn from God. Eventually, Babylon destroys the Temple and takes the people into exile. It's one of the darkest moments in the whole story. (1 Kings 12 – 2 Kings)
6. Return and Rebuilding: After 70 years, the Persians allowed the Israelites to return and rebuild. The Old Testament ends here — the people are home, but still waiting for something more. (Ezra, Nehemiah)

That waiting is important. Throughout the whole story, the prophets kept pointing forward, warning the people, calling them back to God, and promising that one day, a Messiah would come to set everything right. The Old Testament ends with that promise still hanging in the air. For easy understanding, read this bible testament guide. 

What Is the New Testament of the Bible?

The New Testament is the second part of the Bible, made up of 27 books that center on the life, teachings, death, and resurrection of Jesus Christ. It also tells the story of the first Christians and explains how Jesus' message spread across the Roman world.

While the Old Testament points forward to the promised Messiah, the New Testament reveals who that Messiah is. It introduces the new covenant between God and humanity through Jesus, fulfilling promises made throughout the Old Testament. 

Books of The New Testaments

Read the full summaries of each New Testament book in our complete Bible guide.

What's the Summary of the New Testament?

The New Testament opens with four accounts of Jesus. Each Gospel tells its story from a slightly different angle, but they all land on the same events.

1. Jesus is born in Bethlehem to a humble family living under Roman rule, fulfilling the prophecy Micah made more than 700 years earlier about the Messiah's birthplace. (Matthew 1–2, Luke 1–2)
2. Jesus begins his ministry after being baptized and spending 40 days alone in the wilderness, he begins teaching, healing, and gathering disciples. (Matthew 3–4)
3. The Sermon on the Mount is one of Jesus' most important teachings, where he shows that the Law was never just about outward behavior. (Matthew 5–7)
4. Miracles, parables, and growing opposition where Jesus heals the sick, feeds thousands with almost nothing, and tells stories that turn conventional wisdom upside down. Religious leaders feel increasingly threatened by him. (Throughout the Gospels)
5. The Cross and Resurrection where Jesus is arrested, tried, and crucified. Three days later, he rises from the dead. This is the central event of the entire Bible. (John 13–20)
6. The Church was born after Jesus ascended to heaven, and the Holy Spirit came upon his followers at Pentecost. What starts as a small group in Jerusalem spreads rapidly across the Roman world, largely through Paul's missionary journeys. (Acts 1–2)

The rest of the New Testament, mostly Paul's letters and other apostolic letters, is the early church working out what it means to follow Jesus together. How to live, how to treat each other, and what his death and resurrection actually accomplished.

How Are the Old and New Testaments Different?

Now that you've seen both, here's a simple side-by-side comparison of the Old Testament vs. the New Testament. 

The Old Testament was Jesus' Bible. When he taught, debated, or prayed, he was quoting and referencing what we now call the Old Testament. The New Testament hadn't been written yet. The New Testament quotes the Old Testament over 300 times and references it indirectly hundreds more. You can't fully understand what's happening in the New Testament without knowing the story behind it.

Which One Should You Read First: Old or New?

Start with the New Testament, specifically, one of the Gospels.

For a new reader, jumping straight into the Old Testament can feel like walking into a movie three sequels in. There's a lot of history, a lot of names, and a lot of context that clicks much more naturally once you know who Jesus is. So here's a path that actually works:

• Start with the Gospel of John or Mark. John gives you the big theological picture of who Jesus is. Mark is short, fast-moving, and great for first-time readers.
• Then read Acts, it shows you how the early church began and spread, and it reads almost like an adventure story.
• Then work through the rest of the New Testament. The letters will make far more sense once you've met the person they're all about.
• Then go back to the Old Testament. And when you do, you'll find it hits completely differently because now you know where it was all heading.

Don't skip the Old Testament forever, though. It's not an optional background. The more of it you know, the richer the New Testament becomes.

If reading through both still feels like a lot to take on alone, that's exactly what the Elvasma Bible Study Guide is for. It walks you through both testaments in plain, simple language, showing you what each part means, how it connects to the bigger story, and how to actually understand what you're reading rather than just getting through it. It's a good companion to have open alongside your Bible.

The Bottom Line

The Old Testament builds the foundation, it makes the promises, tells the history, and points forward to a savior who is coming. The New Testament shows that the Savior is arriving, and everything that changes because of it.

They're not rivals, and they're not separate books. They're the front half and the back half of the same story, and it's worth reading all of it.

Start with a Gospel. Let the rest unfold from there.

FAQs

Is God different in the Old and New Testaments?

No, and this is one of the most common misunderstandings about the Bible. God's character doesn't change between the two testaments. He is the same God throughout, patient, faithful, and loving in the Old Testament; serious about justice and accountability in the New. What changes between the two isn't God's nature, but how much of his plan has been revealed.

Do Christians really need to read the Old Testament?

Yes. The New Testament assumes you know the older story. Without it, you'll miss the weight of who Jesus is, why his death mattered, and what it means that the Messiah finally came. Reading the New Testament without the Old is like reading the last chapter of a book and wondering why it feels incomplete.

How long does it take to read the Old and New Testaments?

At around 15–20 minutes a day, you can read the entire New Testament in about three months. The full Bible takes roughly a year at that pace. There's no race. Reading slowly with understanding is worth far more than reading fast and feeling lost.