Is the Bible Reliable — Why Should Anyone Trust It?

A Fair Question

Many people today assume the Bible cannot be trusted. They have heard that it was written long after the events it describes, that it was copied and recopied until the original was lost, that it was edited by the powerful to suit their purposes, and that it contradicts itself. If that were true, it would be reasonable to set it aside.

But these are claims about history, and history can be checked. This article does not ask you to believe the Bible is the word of God — that is a question of faith. It asks a simpler question: judged by the ordinary standards historians apply to any ancient document, how reliable is it? The answer surprises many people.

How Do We Judge Any Ancient Text?

Historians ask a few standard questions of any document from the ancient world. How close in time were the surviving copies to the original? How many copies survive, and do they agree? How close was the original to the events it describes? And does outside evidence — other writers, archaeology — confirm what it says?

Let us apply these questions to the Bible, starting with the New Testament, since that is where the central claims of Christianity lie.

Copies: Far More Than Any Other Ancient Work

None of the original manuscripts of any ancient book survive — not of Plato, not of Julius Caesar, not of the New Testament. What we have are copies. The question is how many, and how early.

For most classical works, the answer is: few, and late. The first six books of the Roman historian Tacitus’s Annals, our main source for the reign of the emperor Tiberius, survive in a single manuscript copied in the ninth century — about 800 years after Tacitus wrote. The earliest copies of Caesar’s Gallic War date from roughly 900 years after Caesar. Historians still rely on these texts with confidence.

The New Testament is in a different league. More than 5,000 handwritten Greek manuscripts survive, in whole or in part, along with thousands more early translations into Latin, Syriac, Coptic and other languages. The earliest is a small fragment of John’s Gospel, generally dated to the second century — within a few generations of the original. Complete copies of the whole New Testament survive from the fourth century.

No other ancient text comes close.

Weren’t They Changed in the Copying?

With so many copies made by hand, differences inevitably crept in. Scholars have catalogued them carefully, and the result is reassuring. The overwhelming majority are trivial: spelling, word order, a skipped or repeated word. Because there are so many manuscripts from different places and times, scholars can compare them and reconstruct the original wording with a very high degree of confidence. No central Christian belief depends on a doubtful reading.

The Old Testament gives a striking example. Before 1947, the oldest complete Hebrew manuscripts of the Old Testament dated from around the tenth century AD. Then shepherds near the Dead Sea found caves containing scrolls about a thousand years older, including a complete copy of the Book of Isaiah. When scholars compared them, the text had been passed on with remarkable faithfulness across a millennium.

Written Long After the Events?

A common claim is that the Gospels were written so long after Jesus that they are legends rather than history. The evidence points the other way.

St Paul’s letters, which mention Jesus’s death, burial and Resurrection, were written in the 50s AD — around twenty years after the Crucifixion. In one of them, Paul passes on a summary of the faith that he says he had himself received earlier (1 Corinthians 15:3–8). Many scholars, including sceptical ones, date that summary to within a few years of the events.

Most scholars date the Gospels to between about 65 and 100 AD, and some argue for earlier. Even on the later dates, they were written within the lifetime of people who had known Jesus, and when hostile witnesses were still alive to contradict them. That is very early by the standards of ancient history. The main biographies of Alexander the Great, by comparison, were written more than four centuries after his death.

Does Outside Evidence Confirm It?

The Bible is not the only ancient source to mention Jesus. The Roman historian Tacitus, no friend of Christianity, records that Christ was executed under Pontius Pilate in the reign of Tiberius. The Jewish historian Josephus, writing in the 90s AD, refers to Jesus, and describes the death of a man named James as “the brother of Jesus, who was called Christ.” The Roman governor Pliny the Younger, around the year 112, describes Christians singing hymns “to Christ as to a god.”

Archaeology has also repeatedly confirmed details in the Bible that sceptics once doubted. An inscription bearing the name of Pontius Pilate was found at Caesarea in 1961. The Pool of Bethesda, described in John’s Gospel with five porticoes, was excavated in Jerusalem, as was the Pool of Siloam. A burial box inscribed with the name of Caiaphas, the high priest at Jesus’s trial, was discovered in 1990. In the Old Testament, an inscription found at Tel Dan in 1993 refers to the “House of David” — the first evidence outside the Bible for the dynasty of King David.

Archaeology cannot prove that Jesus rose from the dead. But it shows again and again that the biblical writers knew the places, people and customs they described.

What About the Contradictions?

People often point to differences between the Gospels — in the order of events, the wording of a saying, or the number of angels at the tomb. Some of these are real differences, and Christians have discussed them openly since the earliest centuries.

But differences in detail are exactly what we expect from independent witnesses. Four accounts that agreed word for word would suggest collusion. Courts and historians alike treat agreement on the main facts, combined with variation in the details, as a mark of genuine testimony.

It also matters what kind of writing we are reading. The Bible is a library, not a single book. It contains history, poetry, law, prophecy, letters and parables. A poem is not wrong because it uses imagery, and a parable is not false because its characters are invented. The Catholic Church teaches that the Bible teaches without error the truth God wished to communicate “for the sake of salvation” (Dei Verbum 11). It is not a textbook of modern science, and it was never meant to be read as one.

Who Decided What Went In?

Some claim that the books of the Bible were chosen centuries later by powerful men who suppressed rival gospels. The historical record does not support this. By the late second century, Christians were already treating the four Gospels and most of the letters of Paul as Scripture. The later “gospels” sometimes held up as rivals were mostly written a century or more after the events, and the early Church rejected them precisely because they were late and did not come from the apostles.

The Catholic Church did recognise the final list of books, at councils in the late fourth century. But she did not invent them. She recognised the writings that the churches had received from the apostles and had been reading in worship for generations. For why Catholic Bibles contain more Old Testament books than Protestant ones, see Why Do Catholics Have Seven More Books in the Bible?

Why This Matters

If the New Testament is a reliable historical record, then it cannot simply be dismissed. It confronts every reader with Jesus of Nazareth — a man who claimed to forgive sins, to be one with God, and to rise from the dead, and whose followers were willing to die rather than deny that He did.

That is the step historical reliability makes possible. It does not force anyone to believe. But it means the question of who Jesus is deserves a serious answer.

The Catholic View

Catholics believe something more than that the Bible is reliable history. They believe it is inspired by God, who is its principal author, working through human writers (CCC 105–106). But they do not ask anyone to accept that on the Bible’s word alone. The Church existed before the New Testament was written. She wrote it, preserved it, recognised it, and reads it today within the living Tradition she received from the apostles.

For a non-believer, the reasonable path is the one many converts have taken. Start by reading the Gospels as historical documents. Ask who this Jesus was. If He is who He claimed to be, then the Church He founded, and the Scriptures she treasures, deserve a hearing. The best way to judge the Bible is still the simplest: read it for yourself.