Old Testament vs. New Testament

Two libraries in one book

The Bibleis not a single book but a collection of texts written over roughly a thousand years by dozens of authors in multiple languages. The Old Testament (or Hebrew Bible) was composed between approximately 1200 and 165 BCE in Hebrew and Aramaic. The New Testament was written in Greek between approximately 50 and 120 CE. The gap between the two — in time, language, culture, and theology — is enormous, and the tensions between them have shaped Christian thought from its first century to the present.

The God of the Old Testament

The Old Testament presents a God who is, by any modern moral standard, deeply troubling. He commands the Israelites to commit genocide against the Canaanites (Deuteronomy 20:16-17), kills the firstborn children of Egypt (Exodus 12:29), sends bears to maul children for mocking a prophet (2 Kings 2:23-24), and demands animal sacrifice as a condition of his favor. He is jealous, wrathful, and territorial: “I the Lord your God am a jealous God, visiting the iniquity of the fathers on the children to the third and the fourth generation” (Exodus 20:5).

The Old Testament God is also tribal. He chooses one nation — Israel — as his special people and instructs them to conquer, displace, and sometimes exterminate their neighbors. The moral universe of the Hebrew Bible is not universalist; it is the story of one people’s relationship with their national deity, and the welfare of other nations matters only insofar as it affects Israel.

The God of the New Testament

The New Testament introduces a strikingly different tone. Jesus preaches love of enemies, forgiveness, humility, and care for the poor. The Sermon on the Mount (Matthew 5-7) is widely regarded as one of the great ethical texts of any tradition. Paul extends the promise of salvation beyond Israel to all humanity: “There is neither Jew nor Gentile, neither slave nor free, nor is there male and female, for you are all one in Christ Jesus” (Galatians 3:28).

But the New Testament is not uniformly gentle. Jesus speaks of hell more than any other figure in the Bible. He promises eternal damnation for those who reject him (Matthew 25:46), tells his followers to hate their families for his sake (Luke 14:26), and drives moneychangers from the temple with a whip (John 2:15). Paul endorses the subordination of women (1 Corinthians 14:34-35) and condemns homosexuality (Romans 1:26-27). And the Book of Revelation envisions a final apocalypse of cosmic violence that makes anything in the Old Testament look restrained.

Contradictions between the testaments

The contradictions between Old and New Testament are not minor discrepancies but fundamental theological conflicts. The Old Testament prescribes eye-for-an-eye justice (Exodus 21:24); Jesus repudiates it (Matthew 5:38-39). The Old Testament mandates dietary laws, circumcision, and sabbath observance as eternal covenants; Paul declares them superseded by faith in Christ (Galatians 2:16). The Old Testament promises material prosperity and military victory as rewards for righteousness; Jesus says the meek will inherit the earth and the rich will struggle to enter heaven.

Christians have developed several strategies for handling these contradictions. Dispensationalism argues that God operates differently in different historical periods. Typology reads the Old Testament as foreshadowing the New. Progressive revelation holds that God gradually disclosed more of his nature over time. Critics note that all of these strategies amount to admitting that the Bible contradicts itself while insisting it somehow doesn’t.

Moral evolution

Viewed from outside, the shift from Old to New Testament reflects a broader moral evolution in the ancient world. The tribal, militaristic ethic of the early Israelites was typical of Bronze Age Near Eastern societies. The more universalist, compassion-oriented ethic of the New Testament emerged in a Hellenistic world already influenced by Stoic and Platonic philosophy. The Bible did not invent moral progress; it reflects the moral progress of the cultures that produced it.

This observation poses a problem for believers who claim the Bible is the source of morality rather than a product of evolving human moral understanding. If God is perfect and unchanging, why does his moral instruction change so dramatically between testaments? And if we can recognize that the Old Testament’s endorsement of slavery and genocide is morally wrong, we are applying a standard that comes from outside the Bible — which means the Bible is not, and cannot be, our ultimate moral authority.

What scholarship reveals

Modern biblical scholarship has deepened these tensions rather than resolving them. The Documentary Hypothesis shows that the Pentateuch was assembled from multiple sources with different theological agendas. Textual criticism of the New Testament reveals that many passages were added or altered by later scribes — including the story of the woman taken in adultery (John 7:53-8:11) and the ending of Mark’s Gospel (Mark 16:9-20).

Scholars like Bart Ehrman have demonstrated that the New Testament authors disagreed with each other on fundamental questions: Was Jesus divine from birth (John) or adopted as God’s son at baptism (Mark)? Was salvation by faith alone (Paul) or by faith and works (James)? Did Jesus die as a sacrifice for sin (Paul) or as an example of faithfulness (Luke)? The Bible is not a unified text with a single message but a library of competing voices, and the apparent unity Christians find in it is imposed from outside, not discovered within.

Why this matters

The relationship between the two testaments is not just an academic question. It determines how Christians approach law, politics, and ethics. Those who emphasize the Old Testament tend toward theocracy, retributive justice, and the enforcement of religious law. Those who emphasize the New Testament tend toward mercy, social justice, and the separation of church and state. The same book supports both positions — which is precisely the problem with treating any ancient text as the final word on how to live.