1. Introduction
The Bible, a canonical collection of sacred texts within the Christian tradition, is divided into two major divisions: the Old Testament (OT) and the New Testament (NT). These two Testaments are not merely sequential anthologies but theologically interconnected documents that together form a unified narrative of divine revelation. This article explores the relationship between them by analysing their historical formation, linguistic features, theological continuity, covenantal development, and Christological fulfilment.
2. The Old Testament: Historical Roots and Covenant Foundations
The Old Testament, predominantly written in Biblical Hebrew (with sections in Aramaic), was composed between approximately 1400 BC and 400 BC. It consists of 39 books (in the Protestant canon), organised into the Torah (Law), Nevi’im (Prophets), and Ketuvim (Writings), known collectively in Jewish tradition as the Tanakh.
At the theological core of the OT lies the Mosaic Covenant, established at Mount Sinai. It structured Israel’s identity as God’s chosen people through three categories of law:
- Moral Law – universal ethical commands (e.g. the Ten Commandments, Exodus 20),
- Ceremonial Law – priesthood, sacrifices, feasts (Leviticus),
- Civil Law – governance of Israelite society (Deuteronomy).
The OT covenant is conditional, requiring obedience for blessing (cf. Deuteronomy 28) and anticipates a future redemptive intervention (Isaiah 53; Jeremiah 31).
3. The New Testament: Fulfilment and Christocentric Covenant
The NT, written in Koine Greek between AD 45–95, contains 27 books including the Gospels, Acts, epistles, and Revelation. It presents Jesus Christ as the fulfilment of OT prophecy and the mediator of a New Covenant (cf. Luke 22:20).
Key emphases include:
- Justification by faith (cf. Romans 3:28),
- Salvation by grace (cf. Ephesians 2:8–9),
- Indwelling of the Holy Spirit (cf. Romans 8:9–11).
The NT does not abolish the OT but reinterprets it in light of the person and work of Christ. Jesus declares, “Do not think that I have come to abolish the Law or the Prophets… but to fulfil them” (Matthew 5:17).
4. Comparative Framework of the Testaments
| Dimension | Old Testament | New Testament |
|---|---|---|
| Language | Hebrew & Aramaic | Koine Greek |
| Historical Range | ~1400–400 BC | ~AD 45–95 |
| Covenant Type | Mosaic (conditional, law-based) | New Covenant (unconditional, grace-based) |
| Mediator | Moses | Jesus Christ (cf. Hebrews 8:6) |
| Sacrificial System | Animal offerings (temporary atonement) | Christ’s sacrifice (permanent atonement, Hebrews 10:14) |
| Law | External commandments | Internalised through the Spirit (Jeremiah 31:33, Romans 8:2) |
| Priesthood | Levitical (Aaronic) | Jesus as High Priest (Hebrews 4:14–16) |
| Temple | Physical sanctuary (Jerusalem) | Body of believers as temple (1 Corinthians 3:16) |
| Ethnic Scope | Primarily Israel | Universal to all nations (Galatians 3:28) |
5. The New Covenant in Theological Context
The concept of the New Covenant is rooted in Old Testament prophecy, particularly in Jeremiah 31:31–34 and Ezekiel 36:25–27, where God promises a future covenant not like the one made with the ancestors at Sinai.
The New Covenant:
- Offers total forgiveness (Hebrews 8:12),
- Internalises God’s law (Hebrews 10:16),
- Is mediated through Christ (Luke 22:20),
- Is sealed by the Holy Spirit (Ephesians 1:13–14).
Unlike the Mosaic Covenant, the New Covenant is grounded in divine initiative, not human merit, and is enacted by Christ’s once-for-all sacrifice (Hebrews 9:15).
6. Typology and Fulfilment: Reading the OT in Light of Christ
The NT interprets the OT typologically: events, persons, and rituals in the Old foreshadow New Covenant realities. Examples include:
- Passover Lamb → Jesus as the Lamb of God (Exodus 12 → John 1:29)
- Manna in the wilderness → Jesus as the Bread of Life (Exodus 16 → John 6:35)
- Temple sacrifices → Christ’s atonement (Leviticus → Hebrews 10)
Such typology reveals a theological continuity that is fulfilled, not annulled, in Christ.
7. Continuity and Discontinuity: Law, Grace, and Moral Foundations
While ceremonial and civil laws are fulfilled in Christ and no longer binding (cf. Colossians 2:16–17), the moral law continues to bear relevance, now framed through the law of love (cf. Matthew 22:37–40, Romans 13:8–10).
Key tensions include:
- Grace vs Law (cf. Galatians 3:24–25)
- Faith vs Works (cf. Romans 4:2–5)
- External command vs internal transformation (cf. 2 Corinthians 3:3)
Theological frameworks such as Covenant Theology and New Covenant Theology attempt to systematise these relationships.
8. Application for Theological Study and Preaching
Understanding the Testamental relationship:
- Prevents heretical dichotomies, such as Marcionism (rejection of the OT),
- Supports unified preaching from Genesis to Revelation,
- Equips believers to understand their moral and spiritual inheritance,
- Frames Christian identity not as legalistic but Spirit-led (Romans 8:14).
Preachers should affirm the OT as Christian Scripture (2 Timothy 3:16) while interpreting it Christologically (Luke 24:27).
9. Conclusion
The Old and New Testaments constitute a unified yet progressive revelation. The New does not replace the Old but fulfils it through the person and work of Christ. The New Covenant, prefigured in prophecy and enacted through Christ, represents both a continuity of God’s moral will and a transformation in covenantal administration. The law is fulfilled, the promises realised, and the spiritual temple formed. Together, these Testaments proclaim one Gospel through two covenants—centred on one Saviour.
References
- Beale, G. K. & Carson, D. A. (2007). Commentary on the New Testament Use of the Old Testament. Baker Academic.
- Bruce, F. F. (1988). The Canon of Scripture. InterVarsity Press.
- Goldsworthy, G. (1991). According to Plan: The Unfolding Revelation of God in the Bible. IVP.
- Kaiser, W. C. (2001). The Old Testament in Contemporary Preaching. Baker Books.
- Wright, N. T. (1992). The New Testament and the People of God. SPCK.
- Moo, D. J. (2000). The Epistle to the Romans. Eerdmans.
- Poythress, V. S. (2000). The Shadow of Christ in the Law of Moses. P&R Publishing.
- Schreiner, T. R. (2010). New Testament Theology: Magnifying God in Christ. Baker Academic.