The Reliability of the New Testament, Part 2: Internal and External Evidence Tests


First read: The Reliability of the New Testament, Part 1: Date and The Bibliographical Test

The Reliability of the New Testament: Internal Evidence Test

Some skeptics will consider the Bibliographical Test and respond, “That’s fine. We have what the New Testament authors wrote. But how do we know that they wrote accurately? Maybe they invented a myth.”

Objection 4: We cannot trust the authors of the New Testament to record accurately the events that happened. They are not reliable witnesses.

To answer this objection, we will look at internal evidence and external evidence for the reliability of the Bible. The internal evidence test looks at the writing itself. It analyzes what is written to determine whether we can trust the author. The Internal Evidence Test asks, “Can we trust what the authors wrote? Were they honest and competent?” The External Evidence Test looks for outside information that supports the truth of the New Testament.

Response to Objection 4: The internal evidence and external evidence test show that the New Testament is a reliable historical record.

A. Internal Evidence: Eyewitness Testimony

Read 2 Peter 1:16; 1 John 1:1, and Luke 1:1-4. What do these verses tell us about the testimony of the authors?

The Gospels were based on the memories of people who had close contact with Jesus. They reported what they had seen and heard personally.

Their memories can be trusted for two reasons:

1) Their time with Jesus was the most important thing that ever happened to them. Since the disciples’ time with Jesus was so significant to them, they would likely have remembered the details well.

 Can you remember where you were on Tuesday morning six months before studying this lesson? Probably not. But can you remember where you were when you surrendered your life to Christ and became God’s child? Probably! We remember the details of important events much more than daily life.

2) Jesus told his disciples that the Holy Spirit would bring to their remembrance all that he had said to them (John 14:25–26).

B. Internal Evidence: The Presence of Living Witnesses

At the time the Gospels were written, there were many witnesses still living. These people had seen Jesus and would know if the Gospels included stories that were false.

Some of these witnesses were unbelievers. These critics would have loved to discredit the apostles. If the authors had made a mistake, the critics would have pointed it out. For instance, if the body of Jesus had been still in the tomb, it would have been easy for the Jewish leaders to say, “Here is the body!”

The Gospels tell the story of Jesus feeding 5,000 men, plus women and children. If this story had been false, someone would have said, “I was there that day. It didn’t happen like that. We all brought our own lunches!”

C. Internal Evidence: The Authors Died for Their Faith

The apostles died for their Christian faith. Some of them were tortured; all of them suffered opposition; most of them died as martyrs. People will sometimes die for what they believe to be true, but not for something they know to be false.

If the Resurrection had not taken place, the disciples would have known it. The disciples who had hidden in fear after Jesus’ arrest would not have died for something they knew to be untrue. Their willingness to give their lives for their faith confirms their belief.

The writers of the Gospels were trustworthy and competent. This is internal evidence that we have a reliable New Testament.

Read: What About Contradictions in the Bible?

The Reliability of the New Testament: External Evidence Test

The Internal Evidence Test looks at the writing itself to determine if the author was honest and competent. The External Evidence Test looks for outside information that supports the document. In the case of the New Testament, this test asks, “What evidence exists outside of Scripture for the truth of the New Testament?”

A. Supporting Evidence from Other Early Christian Writers

Early Christian leaders based their faith on the truth of the Gospels. Like the apostles themselves, these early Christians risked their lives for their faith.

Papias was an acquaintance of John the apostle. He wrote that John testified that the Gospel of Mark was based on Simon Peter’s memories of Jesus’ life and ministry. This is external evidence that the Gospel of Mark records an eyewitness account of Jesus’ ministry.

Irenaeus was born around A.D. 125, less than forty years after John wrote his gospel. Irenaeus wrote: “So firm is the ground upon which these Gospels rest, that the very heretics themselves bear witness to them, and starting from these documents, each one of them endeavors to establish his own particular doctrine.”

According to Irenaeus, even heretics in the early church respected the Gospel records. The Gospels must have been considered extremely reliable documents.

B. Supporting Evidence from Non-Christian Sources

What would we know about Jesus and early Christianity if we did not have the Bible? External evidence looks at non-Christian sources that confirm the New Testament record.

Historical references from non-Christians verify much of the New Testament. These include:

  • A letter from Pliny the Younger, governor of Bithynia to Emperor Trajan in A.D. 112
  • The writings of Josephus, a Jewish historian
  • Tacitus, a Roman senator and historian
  • Lucian, a Greek writer from the second century
  • Suetonius, a Roman historian
  • The Talmud, the Jewish commentary on the Law of Moses

These non-Christian sources confirm many aspects of the New Testament accounts:

  • Jesus was crucified under Pontius Pilate at Passover (Tacitus, Josephus, Talmud).
  • His disciples believed that he rose from the dead three days later (Josephus).
  • Jewish leaders charged Jesus with magic and believed he was born of adultery
  • (Talmud). (Even Jesus’ enemies knew that he was doing miracles—they called it magic—and that he had an unusual birth.)
  • Christianity spread to Rome (Tacitus, Suetonius).
  • Nero and other Roman rulers persecuted and martyred early Christians (Tacitus,
  • Suetonius).
  • Christians denied polytheism, lived according to Christ’s teaching, and worshiped
  • Christ (Pliny, Lucian).
  • We know all of the above from secular and Jewish history. This provides outside confirmation that the New Testament is accurate historically.

C. Supporting Evidence from Archaeology

Archaeology is a valuable source of external evidence. Since the nineteenth century, archaeologists have been able to find many locations mentioned in the New Testament. Repeatedly, their study has matched exactly the New Testament record.

Read Apologetics in Action: Apologetics in Action: The Testimony of Sir William Ramsay (1851-1939).

Exhibit 1: The Reliability of Luke’s Writings

Sir William Ramsay used the writings of Luke to study the geography of Asia Minor. He found that Luke was unsurpassed in his knowledge of history and geography. For example, Luke mentions about thirty-two countries, fifty-four cities, and nine islands. In every case Ramsay studied, he found Luke’s account to be accurate.

Exhibit 2: Pilate’s Judgment Seat

John 19:13 refers to a judgment seat where Pilate sat while trying Jesus. “So when Pilate heard these words, he brought Jesus out and sat down on the judgment seat at a place called The Stone Pavement.”

For many years, liberal critics called this story a myth. They argued that we could not trust this story because there is no record of this “stone pavement” in Jewish or secular history.


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The Pavement of John 19:13

However, archaeologists have found this pavement; and it can be seen by visitors to Jerusalem. When the Roman general Titus destroyed Jerusalem, he built barracks above the pavement. When these barracks crumbled, other buildings were built on top. The pavement disappeared. Early archaeologists dug down to the barracks, but no further. During the 1970’s archaeologists dug beneath the barracks and discovered the pavement. This place in the NT was proven to exist.


Exhibit 3: The Pool of Bethesda

John 5 refers to a Pool of Bethesda, with five porches. Again, because there is no record in Jewish or secular sources, skeptics called this a myth. In 1888, archaeologists found the pool while digging forty feet below ground near the Church of St. Anne. The pool had five porches, just as John said.

The New Testament is historically reliable. We do not need to fear that archaeologists will disprove the Bible. As archaeologists dig, they find increasing evidence to support the truth of the Bible.


Jia showed Lee each of these tests for the validity of the New Testament. She showed him that the Bibliographical Test confirms that the New Testament we have today teaches the same doctrine taught by the original manuscripts. She showed him that the Internal and External Evidence Tests confirm the reliability of the New Testament.

“Lee,” Jia concluded, “You may choose to believe the claims of the New Testament or you may choose to reject them. However, you can’t deny that the New Testament is a reliable historical document. There is far greater evidence for the truth of the New Testament than for any other document from the ancient world, either western or Chinese. The New Testament is a trustworthy historical document.”

Review Questions

  1. Respond to the following objection: “We cannot trust the authors of the New Testament to record accurately the events that happened. They are not reliable witnesses.”
  2. List three reasons the New Testament passes of the “Internal Evidence Test.”
  3. What is the Law of Non-Contradiction?
  4. Can anyone demonstrate a genuine violation of the law of non-contradiction in Scripture?
  5. List three lines of evidence that help the NT pass the “External Evidence Test.”
  6. Name two archaeological discoveries that support the historical accuracy of the New Testament.
  7. Quote 2 Timothy 3:16-17.
Mark Bird
Mark Bird
Mark Bird is Professor of Theology and Apologetics at God's Bible School and College.