The podcast, Old Testament vs New Testament: Passion, Poetry and the World’s Greatest Stories, shares that together - the Old Testament and the New Testament make up the Holy Bible. 

The Old Testament contains the sacred scriptures of the Jewish faith, while Christianity draws on both Old and New Testaments, interpreting the New Testament as the fulfillment of the prophecies of the Old.

Pursuit Bible explains that the simplest way to understand it is that the Old Testament was written first and tells the first part of the story. The New Testament was written later and finishes the story.

While the Bible is one collection of books with one powerful, unique message, there are numerous differences between the Old Testament and New Testament.

Old Testament vs. New Testament - What are the differences?

Diffen provides an overview of the differences in history and content between the Old Testament and the New Testament. 

David Kim of Pursuit Bible reiterates that the main difference is that they focus on different parts of one big story. The Old Testament sets up the story and the New Testament continues and finishes it.

David Kim of Pursuit Bible reiterates that the main difference, however, is that they focus on different parts of one big story. The Old Testament sets up the story and the New Testament continues and finishes it.

Compelling Truth adds that In many ways, the Old Testament serves as the foundation for the New Testament.

Teachings of the Old vs the New Testament

Diffen’s New Testament vs. Old Testament continues to explain the differences between them. The Old Testament focuses on God’s dealings with a single nation.

The New Testament, on the other hand, focuses more on all nations. 

The New Testament’s message is to lead people to follow the example of Jesus more closely. 

We learn about more significant differences in focus, prophecy, and practice of worship and covenant of the testaments in the article, What are the differences between the Old and New Testaments? 

There is a difference in focus. The Old Testament chronicles God's power and works, looking toward the coming Messiah. The New Testament reveals Jesus as the Messiah, looking back at His life and teachings as the basis for the church and the spread of the gospel.

There is a difference in prophecy. Most Old Testament prophecies look forward to the future and were unfulfilled at the time of the Old Testament's completion. The New Testament highlights the fulfillment of many of the Old Testament's prophecies, including more than 300 in the life of Jesus Christ.

There is a difference in the practice of worship. Much of the Old Testament focused on the tabernacle or temple as the central place of worship. Many details were included in the development of offerings, festivals, and related practices. In the New Testament, Jesus offered Himself as the focus of worship, claiming to be the way, the truth, and the life, and that no one could come to the Father except through Him. God's presence now lives on the inside of believers and believers themselves are now called the “Tabernacle of God.” (John 14:6).

There is a difference in the covenant. The Old Testament emphasized the Mosaic covenant with its focus on the Law of the Lord. The New Testament began a new covenant in which Jesus came as a fulfillment of the Law. No longer would the Jewish people (or Gentiles) need to fulfill the Law to find atonement; Jesus offered forgiveness and eternal life to all who believed in Him.

Relationship Between Old and New Testament

In many ways though, these differences are complementary. While the Old Testament is foundational; the New Testament builds on that foundation with further revelation from God. 

Got Questions shares that the Old Testament establishes principles that are seen to be illustrative of New Testament truths. 

The Old Testament contains many prophecies that are fulfilled in the New. The Old Testament provides the history of a people; the New Testament focus is on a Person. The Old Testament shows man's inability to remain faithful to God ); while the New Testament shows God's response to that unfaithfulness…he remains faithful and even comes down to fulfilling our part of the agreement on our behalf so that we would no longer have to be subject to the curses of breaking the covenant but rather be justified to receive the blessings of it.  “His own arm will save.”

Intelligence Squared adds that Christianity interprets the New Testament as the fulfillment of the prophecies of the Old.

The Sum of Its Parts

Got Questions concludes in summary that the Old Testament lays the foundation for the coming of the Messiah who would sacrifice Himself for the sins of the world.

The New Testament records the ministry of Jesus Christ and then looks back on what He did and how we are to respond. Both testaments reveal the same holy, merciful, and righteous God who condemns sin but desires to save sinners through an atoning sacrifice. In both testaments, God reveals Himself to us and shows us how we are to come to Him through faith.

The Bible and its message guide our hearts and our very existence in this world. Both testaments are complementary, teaching us to come to God in faith, to be redeemed, and come out victorious over sin.  

“All Scripture is given by inspiration of God and is profitable for doctrine, for reproof, for correction, for instruction in righteousness.” 2 Timothy 3:16