Old Testament theology—What is it?

from the old testament

• The main theme in the Old Testament is found to be God initiating relationship with people, culminating in the coming Messiah (Genesis 3:15; Isaiah 9:6–7; Micah 5:2).
• In Jeremiah, the prophecies reach an apex in the revelation of a coming New Covenant. The writer of Hebrews ties this most strongly to the arrival and life of Jesus Christ.
• Though written over thousands of years by many people, the Old Testament books contain an organized presentation of God's creation, humanity's rebellion against Him, and His actions to reestablish relationship with mankind. This revelation begins in the very first verse: "In the beginning, God created the heavens and the earth" (Genesis 1:1). People of faith apply that faith to this verse, and all Scripture that follows through Revelation, as truth from God.
• The Old Testament gives vivid pictures of God's justice, grace, mercy, and love (Psalm 89:14; Exodus 34:6–7; Hosea 11:4). It provides hope for redemption, which God offers through Jesus Christ (Isaiah 53:4–6; Jeremiah 31:31–34).
• The Old Testament establishes a historical framework through which we understand who God is (Exodus 3:14; Psalm 100:3), sinful human nature (Genesis 6:5; Psalm 51:5), our need for a Savior (Genesis 3:15; Isaiah 53), and God's promise to redeem (Genesis 12:3; Jeremiah 31:31–34). Its primary focus is on how God interacted with the nation of Israel (Exodus 19:5–6; Deuteronomy 7:6), His chosen people through whom He chose to reveal Himself to the world (Isaiah 43:10; Amos 3:2).

from the new testament

• The Holy Scriptures testify that God used writers throughout time to communicate His desire and plan for people. "For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit" (2 Peter 1:21).
• John poetically ties Jesus to this eternal Word from God, equating Him with God, as the Creator, the Dispeller of darkness, and timeless (John 1:1–5). Jesus ties Himself to this truth in John 14:6: "Jesus said to him, 'I am the way, and the truth, and the life. No one comes to the Father except through me.'"
• The New Testament fulfills and completes the promises and prophecies of the Old Testament, revealing the full revelation of God through Jesus Christ. It shows that Old Testament theology—God’s unfolding plan revealed through covenants, law, and prophecy—is centered on the coming Messiah, who perfectly fulfills the law and prophets (Matthew 5:17; Luke 24:25–27).
• The New Testament emphasizes that salvation, hinted at in the Old Testament, is fully realized through Christ’s life, death, and resurrection (Romans 1:2–4; Hebrews 1:1–3).
• It also establishes the New Covenant promised in the Old Testament (Jeremiah 31:31–34) and explains how believers now relate to God by grace through faith (Hebrews 8:6–13; Ephesians 2:8–9). Thus, New Testament theology builds directly on the foundation laid in the Old Testament, making its teachings essential for understanding the full story of God’s redemption.

implications for today

Understanding Old Testament theology is crucial to understanding the full story of God’s relationship with humanity—showing His justice, mercy, faithfulness, and the promise of redemption through the Messiah. The New Testament cannot be understood without understanding the Old. By studying how God revealed Himself through covenants, law, and prophecy, we gain deeper appreciation for the foundation of our faith and the seriousness of sin, as well as the hope that comes from God’s plan to restore us. Knowing Old Testament theology helps us see Jesus not as a disconnected figure, but as the fulfillment of centuries of God’s promises, strengthening our trust in His faithfulness. It also shapes how we live, reminding us to respond to God’s holiness with obedience, repentance, and worship, while embracing His mercy and grace. In a world that often misunderstands God’s character, Old Testament theology anchors us in His unchanging truth and calls us to live in faithful relationship with Him.