How does OT relate to NT?
Question 10026
Many Christians treat the Old Testament as a kind of backstory — useful for context, but not particularly necessary once you have the New Testament in hand. Others approach both Testaments as though they are essentially interchangeable, applying Old Testament promises and warnings with little attention to the differences between the covenants they represent. Both approaches miss something important. The relationship between the two halves of the Bible is one of the richest and most rewarding areas of biblical study, and getting it right changes how you read almost every page of both.
Promise and Fulfilment
The most fundamental relationship between the Old and New Testaments is that of promise and fulfilment. The Old Testament is saturated with anticipations, types, and predictions that find their realisation in the person and work of Jesus Christ. The New Testament writers understood this without exception. Matthew structures his Gospel around the repeated formula “that it might be fulfilled which was spoken through the prophet.” Luke records Jesus explaining to the disciples on the road to Emmaus that “everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled” (Luke 24:44) — covering all three divisions of the Hebrew Bible.
Paul’s summary in Galatians 3:24 captures the pedagogical dimension of this relationship: “the law was our guardian until Christ came, in order that we might be justified by faith.” The Greek word translated “guardian” is paidagōgos — the slave in a wealthy household who accompanied children to school, ensuring they arrived safely and behaved properly, but who was not the teacher himself. The law functioned as that custodian, preparing and directing Israel toward the one who was coming.
Continuity: One God, One Story
The God of the Old Testament and the God of the New Testament are the same God. This sounds obvious, but it needs stating clearly because the second-century heretic Marcion proposed otherwise — that the wrathful deity of the Old Testament was a lesser, inferior being, while the God Jesus revealed was a God of pure love. The church rightly rejected this as a fundamental distortion. The God who destroyed Sodom is the same God who sent His Son to die for sinners. The God who commissioned Joshua is the same God who raised Jesus from the dead. His attributes — holiness, justice, love, faithfulness, power — are entirely consistent across both Testaments.
The story is continuous. Creation, fall, the call of Abraham, the exodus, the monarchy, the exile, the return — these are not a preamble to be discarded once the New Testament begins. They are the narrative within which the New Testament events are embedded and from which they draw their meaning. The cross makes no sense without the sacrificial system. The resurrection makes no sense without the exile and the promises of restoration. Paul’s argument in Romans 4 about Abraham’s justification by faith only works if the reader knows the Abraham narrative of Genesis. The New Testament constantly assumes the Old.
Discontinuity: New Covenant, New Community
Continuity does not mean uniformity. The New Testament is equally clear that something genuinely new has arrived in Christ — that His coming marks a decisive change in the administration of God’s purposes. The author of Hebrews describes the first covenant as “obsolete” and “growing old” and “ready to vanish away” (Hebrews 8:13), because the better covenant it pointed toward has now been inaugurated in Christ’s blood.
This matters in several areas. The sacrificial system, centred on the Jerusalem temple and its Aaronic priesthood, has been fulfilled and superseded. There are no more animal sacrifices because “Christ, having been offered once to bear the sins of many, will appear a second time, not to deal with sin but to save those who are eagerly waiting for him” (Hebrews 9:28). The food laws and purity regulations that distinguished Israel from the nations are no longer operative, because in Christ the dividing wall of hostility has been broken down (Ephesians 2:14).
The community in which God’s purposes are now being worked out has also changed. The church is not the continuation of national Israel. God’s programme for Israel and His programme for the church are distinct, though related — a distinction that will be fully resolved at the return of Christ, when God fulfils His outstanding promises to the nation of Israel (Romans 11:25-27) alongside His purposes for the church.
Type and Antitype
One of the richest dimensions of the Old Testament’s relationship to the New is typological — the way Old Testament persons, events, and institutions function as divinely intended foreshadowings of New Testament realities. Adam is described by Paul as “a type of the one who was to come” (Romans 5:14), with Christ as the last Adam who undoes what the first Adam’s disobedience accomplished. The Passover lamb finds its antitype in Christ, “our Passover lamb” (1 Corinthians 5:7). The tabernacle and its furniture are described in Hebrews as “a copy and shadow of the heavenly things” (Hebrews 8:5).
Reading typologically is not reading arbitrarily — it is following the New Testament’s own interpretive lead. The connections are not invented by clever readers; they are established by the inspired authors who wrote both Testaments under the guidance of the same Holy Spirit.
So, Now What?
Read the Old Testament as necessary reading, not optional background. Read it asking what it reveals about God, what it anticipates about Christ, and what it explains about the New Testament texts that constantly reference and assume it. Read the New Testament alongside the Old, because its authors expected readers who knew their Hebrew Scriptures and who would recognise the allusions, quotations, and typological connections woven into every page. The Bible is one book telling one story — and the only way to understand either half fully is to read it that way.
“And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself.” Luke 24:27
