My son just turned three and is in the stage of life where his response to everything I say is “why?”. Sometimes I have patience and calmly explain something for the hundredth time, yet other times my patience wears thin and my response is “because, buddy, that’s just how it is”. I remember feeling this way when trying to explain why I believe the Bible to an unbelieving friend. She asked, ‘why, why, why?’ and I didn’t have any concrete answers other than ‘I just believe.’ In 1 Peter 3:15, Christians are called to give a defense for the hope that is in us, and to obey this exhortation we must study why we believe what we believe.

There are many helpful resources on the Canon of Scripture, and I hope you join me in using this brief article to kick start your study of why Christians believe the canon was divinely authored and therefore is completely trustworthy.

What is the Canon?

The canon of Scripture is the list of all the books that belong in the Bible. The word canon is of Greek origin and means “measuring rod.” We use the phrase Canon of Scripture to describe the compilation of books in the Bible as the standard by which all truth is measured. It is crucial for Christians to trust that the books in the Bible are God’s very words, have absolute authority, and are without error. Everything a Christian does is based on the belief that God’s Word is true. Studying how the canon was recognized will help solidify our trust in God’s Word.

How Was the Canon Recognized?

It was necessary for all books in the bible to pass the test of divine authorship to be recognized as canonical.

Old Testament Books

We are told in Exodus 31 that the very finger of God carved the Ten Commandments on two tablets of stone. Although the rest of Scripture was not written by the very finger of God, God chose to communicate His truth mainly through prophets. Prophets were ordinary men who were chosen by God and empowered by the Holy Spirit. God said of the prophets that He would put His words in their mouths, and they would speak all that God commanded them (Deut. 18:18-20, Jer. 1:9). The same Spirit that divinely authored Scripture empowered the early church fathers to recognize which books of the Bible were inspired and which were merely man-made. Specific criteria—validation from historical sources (extrinsic evidence) and consistency of themes throughout the whole of Scripture (intrinsic evidence)—were used to recognize the divine authorship of the canon.

Historical Validation: Extrinsic Evidence

Other Jewish documents were used as extrinsic evidence for the validation of Scripture. Wayne Grudem points out that in Rabbinic literature, it is repeatedly stated that the Holy Spirit departed from Israel in the function of inspiring prophecy. “After the latter prophets Haggai, Zechariah, and Malachi had died, the Holy Spirit departed from Israel…” (Systematic Theology, pg. 56). Therefore, the Old Testament canon was completed in 435 B.C. when Malachi, the last prophet inspired by the Spirit, spoke.

Thematic Cohesion: Intrinsic Evidence

The intrinsic evidence for the validation of Scripture was that the theme of God’s redemption was consistent throughout. The Catholic books titled the Apocrypha, for instance, teach of faith plus works, which is contrary to the theme of redemption by grace through faith found throughout the rest of Scripture. Since the apocryphal books are not in agreement with the whole of Scripture (and were not divinely authored), those seven books are excluded from the Protestant canon.

New Testament Books

Apostolic Authority

Like the prophets of the Old Testament, the apostles were granted authority from God to write the Scriptures through the guidance of the Holy Spirit (2 Peter 3:2, Acts 5:2-4, John 16:13-14). In John 14:26 Jesus promises the apostles that, “the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you.” We recognize the books written by the apostles Matthew, John, Paul, James, and Peter to meet the criteria of divine authorship.

Apostolic Association

As for the five books of the New Testament that were not written by apostles (Mark, Luke, Acts, Hebrews, and Jude), four of them were recognized due to the human authors’ close association to the apostles and first-hand experience of the apostles’ testimony. Mark was the apostle Peter’s companion (1 Peter 5:13), whom the apostle Paul also vouched for (2 Timothy 4:11, Col. 4:10). Luke, who also authored the book of Acts, was a companion to the Apostle Paul (Col. 4:14). And Jude is connected to the Apostle James (Jude 1).

Gospel Glory

That leaves the book of Hebrews. Hebrews was originally recognized by the early church fathers to meet the first criteria of divine authorship based on the belief that it was written by Paul. However, scholars no longer believe Paul to be the author. Since the second criteria still prove true, it is due to the book’s intrinsic qualities and consistency of truth that we recognize with the early church fathers that this book is indeed authoritative. As Wayne Grudem so eloquently states it, “The majestic glory of Christ shines forth from the pages of the epistle to the Hebrews so brightly that no believer who reads it seriously should ever want to question its place in the canon” (Grudem, pg. 63).

Why it Matters?

Based on the criteria of divine authorship and consistency of truth, we can say with confidence that there are no books in the Bible that shouldn’t be there, and there are no books outside of the Bible that should be included in our canon. We have the complete, perfect, inerrant Words of God written in the pages of Scripture. There is nothing to be added: no present-day revelation, or vision, or ‘relevant’ message. Our pastor recently recited the quote that, “If you want to hear God speak, then read the Bible out loud.” We don’t need new or flashy words from God when we have His Word solidified for us. We can have complete confidence and assurance that we aren’t missing out on crucial information about God and the salvation He offers.

Not only is God’s Word complete, it is what makes us complete. All Scripture is profitable that we may be complete – equipped for every good work (2 Timothy 3:16-17). To my Catholic, Mormon, Jehovah’s Witness, Islamic, and other religion friends: the One and Only God has spoken. It is our responsibility to test and examine the truth. It is our responsibility (with the help of the Holy Spirit) to be convinced of the complete authority of the Canon of Scripture because it is from God Himself. No other authority is as trustworthy, and no other message gives us life and purpose.

Editor's Note: This originally published at Thinking & Theology.