For readers not familiar with the term, the “canon” of Scripture is the list of books that God’s Old and New Testament people learned to recognize as given by inspiration through God’s prophets and apostles.

Your question is exceedingly practical for every Christian. If Scripture is our guide for faith and life—and we stake our eternal life on what it tells us—we want to make sure that we are paying attention to the very words of God himself.

In both Old and New Testament times many books that were not included in the canon claimed inspiration. So how do we know that the Old Testament and New Testament church accurately evaluated which books God had given by inspiration?

For the Old Testament canon we have an advantage. The canon of the Old Testament was firmly set before the time of Christ. Jesus confirms that they got it right. For example, Jesus told the disciples on the first Easter evening, “Everything must be fulfilled that is written about me in the Law of Moses, the Prophets and the Psalms” (Luke 24:44). What is fascinating is that Jesus used the threefold division of the books of the Old Testament canon that was common among the Jews at that time. Consider also his words in John 5:39. As he taught some Jews, he made this statement, “You diligently study the Scriptures because you think that by them you possess eternal life. These are the Scriptures that testify about me.” By speaking of the “Scriptures,” Jesus uses the single comprehensive name for the Old Testament canon and urges the Jews to go back to those books to find Scripture’s witness to him.

We don’t have the same direct confirmation from Jesus’ mouth for the New Testament canon. Yet God didn’t leave the church in the dark. The books God intended for the New Testament canon were all written before the death of the last surviving apostle, John. This “disciple whom Jesus loved” was of great value to the early church in sorting out authentic inspired writings from counterfeits. All the books of the New Testament existed before the end of the first century. Some of them were written by those who were eyewitnesses to the ministry of Jesus.