Why should Christians study the Old Testament?

You Cannot Understand the New Without the Old

The Bible is a progressive revelation — God reveals himself and his plan across its 66 books, building from the foundation laid in Genesis to the fulfilment found in Revelation. If you skip the first half of any great book and try to understand the ending, you will be lost. The same is true of Scripture. The New Testament assumes you have read the Old. The characters, covenants, sacrificial system, laws, and prophecies of the Old Testament are the soil in which the New Testament grows.

Without the Old Testament, you would come to the Gospels and not know why the Jewish people were looking for a Messiah, what kind of Messiah they expected, or how to identify Jesus of Nazareth as that Messiah. You would not understand the Last Supper without Passover, the cross without the sacrificial system, or the resurrection without the Psalms. As Augustine wrote: "The New Testament is hidden in the Old; the Old Testament is unveiled in the New."

Jesus is Hidden on Every Page

The Old Testament is saturated with prophecies pointing to Jesus — written centuries before his birth, yet fulfilled in specific detail:

• His birthplace — Bethlehem (Micah 5:2)
• His manner of death — crucifixion, including the casting of lots for his clothes (Psalm 22:1, 7–8, 14–18)
• His resurrection — "you will not abandon me to the realm of the dead" (Psalm 16:10)
• His suffering on our behalf — the entire chapter of Isaiah 53, written 700 years before Christ
• His ministry and mission — Isaiah 9:2; 52:13; 61:1

These prophecies are so specific that sceptics often argue they must have been written after the fact — which is itself testimony to their remarkable accuracy. Jesus himself used the Old Testament to explain who he was: "Beginning with Moses and all the Prophets, he explained to them what was said in all the Scriptures concerning himself" (Luke 24:27).

It Explains Jewish Customs and Context

Much of the New Testament only makes sense against the backdrop of Jewish life, law, and culture. Without the Old Testament you will not understand:

• Why the Pharisees were so concerned with hand-washing and sabbath rules — they had added hundreds of oral traditions on top of God's law
• Why Jesus' cleansing of the temple was such a dramatic act — the court of the Gentiles had been turned into a market
• Why Paul's arguments in Romans and Galatians about law, faith, and Abraham were so compelling to Jewish readers
• What Jesus meant when he said he came not to abolish the law but to fulfil it (Matthew 5:17)

It Provides Proof That the Bible is God's Word

One of the strongest arguments for the divine inspiration of Scripture is fulfilled prophecy — and the Old Testament is filled with it. Daniel 7–12 contains detailed prophecies about the rise and fall of world empires — the Babylonian, Medo-Persian, Greek, and Roman — written in the 6th century BC but fulfilled over the following centuries with extraordinary precision.

No other religious book in history makes the same volume and specificity of predictions and sees them fulfilled. The Old Testament's prophetic track record is one of the most powerful reasons to trust the Bible as the inspired Word of God rather than a collection of human writings.

It Teaches Us How to Live

The Old Testament is not just history — it is a school of wisdom for the Christian life. The lives of its characters serve as both warnings and encouragements:

• Trust God in impossible circumstances — Daniel in the lions' den (Daniel 6); the three friends in the furnace (Daniel 3)
• Stand firm in your convictions — Daniel refusing the king's food (Daniel 1)
• Confess sin quickly and sincerely — Saul's rationalising versus David's broken repentance (1 Samuel 15; Psalm 51)
• Do not toy with sin — Samson's slow compromise leading to catastrophic loss (Judges 13–16)
• Our choices affect those around us — both for harm (Genesis 3) and for blessing (Exodus 20:5–6)

Paul makes this explicit: "These things happened to them as examples and were written down as warnings for us" (1 Corinthians 10:11).

It Reveals More of God's Character

Some Christians treat the Old Testament God as harsh and the New Testament God as loving — as if they are two different beings. But the God of the Old Testament is the same God who sent his Son to die for sinners. In the Old Testament we see God's holiness, justice, patience, faithfulness, and tender love in vivid detail. The Psalms alone contain more raw, honest theology about the character of God than almost any other literature in history.

"The LORD, the LORD, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness." — Exodus 34:6

This is not a different God from the one revealed in Jesus. It is the same God — his character now made fully visible in the person of his Son.

It Helps Us Understand Prophecy Yet to Be Fulfilled

Many Old Testament prophecies have not yet been fulfilled — they point to events still to come: the return of Christ, the restoration of Israel, the final judgment, and the new creation. Without the Old Testament, books like Revelation and much of Daniel become almost impossible to interpret. The Old Testament provides the framework through which we understand what God has promised and where history is heading.

For a detailed academic treatment of this topic, Western Seminary's article 7 Reasons to Study the Old Testament is an excellent scholarly resource worth reading in full.

In Summary

The Old Testament is not a relic or an optional supplement. It is the first half of God's story — the half that explains the problem, establishes the promises, and prepares the way for the solution. To neglect it is to read a letter with the first pages torn out. The whole counsel of God is available to us. We should not settle for less.