What is the academic field of Biblical Theology?

from the old testament

• Because of its focus on progressive revelation and because many themes of Scripture find their starting point in Genesis, that book is foundational to Biblical Theology. It demonstrates God as Creator, man in God’s image, the entrance of sin, and the promise of a Deliverer (Genesis 1–3). These themes that started there grow and reverberate throughout the entire Bible.
• The covenant with Abraham (Genesis 12:1–3) becomes a key thread that continues the theme of a Deliver but also expands to a focus on nations. God promises land, offspring, and blessing to Israel who will be a blessing to the nations. This is later developed through covenants with Israel (Exodus 19) and David (2 Samuel 7).
• Another example of a theme in Scripture is the Exodus. While a historical rescue, it becomes a recurring pattern of God’s redemptive power (Deuteronomy 5:15; Hosea 11:1), with the Passover lamb anticipating a greater deliverance.
• Similarly, the promises of a coming King in Psalm 2 and the Suffering Servant in Isaiah 53 show that the Old Testament is preparing the reader for something greater. A Biblical Theologian helps to link these ideas to show a unified message of salvation in Scripture.
• Biblical Theology also helps trace other themes such as the movement from tabernacle to temple, showing how God dwells with His people—from the garden (Genesis 3:8) to the wilderness (Exodus 25:8) to the permanent structure in Jerusalem (1 Kings 8)—anticipating the final dwelling of God with man (see Revelation 21:3).

from the new testament

• Jesus was using Biblical Theology when He showed how the Old Testament pointed toward Him: “And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself” (Luke 24:27).
• The Gospel of Matthew is a particularly clear example of how Jesus fulfilled Old Testament prophecies and themes. He is the greater Moses (Deuteronomy 18:15; Acts 3:22-23), the true Israel (Matthew 2:15), and the promised King from David’s line (Matthew 1:1).
• Hebrews develops the theme of Christ as the superior High Priest (Hebrews 4:14) and perfect sacrifice (Hebrews 10:14). The priesthood, tabernacle, and sacrificial system are all shown to be types that find fulfillment in Him (Hebrews 9:11–12).
• Paul’s letters likewise show the development of the promise to Abraham fulfilled in the gospel. In Galatians 3:8 He said, “the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.” While Jesus was the final revelation of the gospel, it was already given in a small part to Abraham. Abraham received more clarity on the promise that God first revealed in Genesis 3:15.
• In Romans, Paul presents Adam and Christ as representative heads of humanity (Romans 5:12–19), connecting creation, fall, and redemption as an overarching theme. The book of Revelation completes the story by showing the restoration of creation and the consummation of God’s kingdom.
• Notice that Biblical Theology in the New Testament isn’t just about citing the Old Testament; it’s about showing how all Scripture fits together in God’s unfolding, Christ-centered plan.
• Some caution at this point is warranted. The Old Testament was not exclusively about salvation, but the New Testament’s primary focus is salvation. This means the Old Testament has more threads than simply salvation. Because of the New Testament’s focus on salvation, some have attempted to make everything in the Old Testament also about salvation, collapsing and spiritualizing all of the promises into salvific ones, and thus being fulfilled in Jesus’ first arrival. However, given the expanded focus of the Old Testament, it is more consistent to understand that not all of the themes that began in the Old Testament have been fully worked out. Several passages, including Romans 11:25–27 and Revelation 20:1–6 anticipate a future fulfilment of Israel-specific promises, completed at Jesus’ second coming (Acts 1:6–7).

implications for today

Biblical Theology strengthens our understanding of Scripture as a coherent whole rather than a collection of disconnected teachings. It helps us avoid cherry-picking isolated verses and instead appreciate how each passage fits within God’s redemptive story. For example, understanding the tabernacle in Exodus makes Christ’s role as the final High Priest and our access to God more profound.

This field also protects us from theological error. When we trace a theme like kingdom or covenant across both testaments, we see how they relate and how God added details over time. However, as we trace the various themes, we must be careful not to squeeze an Old Testament passage that did not refer to salvation to make it fit into the New Testament’s focus on salvation. Our goal should also be to understand a promise the same way as the original author.

Practically, Biblical Theology deepens our worship. It shows us that from the beginning, God has been working toward a goal of redeeming a people for Himself through Jesus Christ. That story gives meaning to our personal walk, reminds us of God’s faithfulness, and encourages us to wait patiently for the final completion of all God’s plan.

By practicing Biblical Theology, we become better readers of the Bible—not just knowing what it says, but understanding why it says it, how it fits into the whole, and how it points to Christ.