The Scriptures bear witness about themselves in various ways that they are the true word of God, and the Holy Spirit efficaciously applies this witness to give the Christian confidence in the written word of God.


The Bible claims in various ways that it is the word of God himself. At times, God spoke directly to the prophets of old and told them to write his words down, even going as far as to write his law himself and give it to Moses. New Testament claims that God “breathed out” all Scripture and that those who wrote were guided by the Holy Spirit; these claims constitute both the Old and New Testaments as God’s own words. Rather than being convinced by multiple rational proofs, Christians are ultimately convinced of the truthfulness of these claims by the internal witness of the Holy Spirit to their validity. The Spirit enables Christians to trust in God’s word and gives us assurance in the face of doubt that God assuredly speaks to us through the pages of Holy Scripture.

The Bible is a book that says many things about God, humanity, sin, salvation, and the goal of all of history. At the same time, the Bible is a book that says a lot about itself. So, what does the Bible say about itself in terms of its authority, and how do these statements relate to the internal witness of the Holy Spirit?

Biblical Teaching

The Bible is replete with statements about God speaking to his people and his people recording those words in holy writ: “Then the Lord said to Moses, ‘Write this as a memorial in a book and recite it in the ears of Joshua, that I will utterly blot out the memory of Amalek from under heaven” (Ex. 17:14; cf. 24:4). In other cases, the Scriptures record that God himself wrote his word, as in the administration of his law: “The Lord said to Moses, ‘Come up to me on the mountain and wait there, that I may give you the tablets of stone, with the law and the commandment, which I have written for their instruction” (Ex. 24:12; cf. 31:18; 34:1). These statements set the Bible on an entirely different plane than any other book. The Bible itself claims that God is its ultimate author: “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work” (2 Tim. 3:16–17). The apostle Paul’s statement places a blanket of divine inspiration over the entirety of the Scriptures, both Old and New Testaments. What we find in the various statements from the Old Testament regarding God’s authorship of the written word, Paul identifies as the result of God breathing it out. The divine inspiration of Scripture, however, does not negate the fact that human authors also wrote the Bible.

Biblical Authorship

The Bible ultimately has two sources, God and the human author. We find this idea present in several places. We noted how God instructed Moses to write down his words—God told Moses what to write. In other cases, God gave prophets visions, which they subsequently recorded in writing (e.g., Dan. 7:1ff). Beyond direct instruction or visions, God inspired the authors of Scripture through the Holy Spirit to record divine revelation:

“Concerning this salvation, the prophets who prophesied about the grace that was to be yours searched and inquired carefully, inquiring what person or time the Spirit of Christ in them was indicating when he predicted the sufferings of Christ and the subsequent glories. It was revealed to them that they were serving not themselves but you, in the things that have now been announced to you through those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look” (1 Pet. 1:10–12).

Peter observes that the Old Testament prophets were inspired to write about the coming Messiah and that God revealed to them that they were ultimately serving the church in future ages. At the same time, they wrote down more than they actually knew because they searched and inquired diligently what type of person and time the Messiah would arrive—they wrote under the inspiration of the Spirit of Christ. This means that we can speak of the dual authorship of the Scriptures, God and humans.

Doctrinal Implications

The doctrinal implications of the ultimate divine authorship of the Scriptures is significant. It means that, though the Bible is a book, it is a book unlike any other—it is of divine origin. It also means that Christians determine the authority of this book on the basis of its divine authorship. In the words of the Westminster Confession of Faith (1647), “The authority of the Holy Scripture, for which it ought to be believed, and obeyed, dependeth not upon the testimony of any man, or church; but wholly upon God (who is truth itself) the author thereof: and therefore it is to be received because it is the Word of God” (I.iv).

In the simplest of terms, Christians must believe and obey the word of God because God wrote it. And we know that God wrote it because the Bible says so. In the history of theology, not all Christians agree on this point. The Roman Catholic Church argues that we must believe the Bible because the church has identified it as the word of God: in short, the church gave birth to the Bible. Protestant theologians, however, instead argue that the Bible gave birth to the church, and hence the church must both acknowledge and submit to God’s word. But such an understanding of God’s word might lead people to believe that they are running in an intellectual circle—the Bible is God’s word because the Bible says so? Are there not many so-called holy books that claim divine origins? How do we set apart the Bible’s teaching from similar claims?

To confirm the authenticity of the Scripture’s self-attesting character, Protestant theologians have historically appealed to the doctrine of the internal witness of the Holy Spirit. The Westminster Confession, for example, notes that there are many noteworthy things about the Scriptures: the efficacy of the doctrine, the heavenly nature of its matter, the beauty of its style, the consent of its various parts, and its perfections. The Confession nevertheless avers that all of these things abundantly demonstrate that the Bible is the word of God, but “our full persuasion and assurance of the infallible truth and divine authority thereof, is from the inward work of the Holy Spirit bearing witness by and with the Word in our hearts” (I.v). In other words, fallen sinners will never humbly submit to the word of God. Rather, the Holy Spirit must first convict sinners of their need for repentance so that they will trust in Christ for their salvation. Once the Spirit has tamed our sinful hearts, we no longer come to the Scriptures with malice and rebellion but as hungry children seeking bread from our heavenly Father. But beyond his work of regeneration and effectual calling, the Spirit positively enables us to trust in God’s word and gives us assurance in the face of doubt that God assuredly speaks to us through the pages of Holy Scripture. The Spirit works in concert with the written word of God to convince us of its truthfulness.

An implication of the self-attestation of Scripture and the internal witness of the Spirit is that God is his own interpreter. Another way of saying this is that Scripture interprets Scripture (analogia Scripturae). While historical contexts, commentaries old and new, and linguistic studies are certainly helpful tools in the interpretive process, the Bible is its own interpreter. We find this principle on both large and small scales. In the big picture, the New Testament interprets the Old Testament. According to some sources, the New Testament cites the Old Testament nearly 900 times. When Jesus was asked what the greatest commandment in the Bible was, for example, he cited Deuteronomy 6:5, “You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment” (Matt. 22:37). From Christ’s statement we know that from the 613 commandments in the Old Testament, this is the first and greatest. The mutually interpretive relationship between the Old and New Testaments rests on the doctrine of the plenary inspiration of the Scripture. That is, if the Holy Spirit inspired all of Scripture, then regardless of the numerous human authors, the message of the Scriptures is consistent across the whole canon. We cannot therefore pit one part of Scripture against another.


In the end, Christians can rejoice in the knowledge that God has inspired the Bible, as numerous passages attest. The self-attesting character of the Scriptures and the accompanying internal witness of the Holy Spirit is a great source of comfort and assurance. When we have doubts about the authority of God’s word, we can turn to Scripture and pray for the Spirit to allay our fears. As Paul wrote to the Thessalonians, “When you received the word of God, which you heard from us, you accepted it not as the word of men but as what it really is, the word of God, which is at work in you believers” (1 Thess. 2:13). Paul recognized Jesus’s teaching, who told his disciples, “For it is not you who speak, but the Spirit of your Father speaking through you” (Matt. 10:20; Luke 10:16; John 13:20). Thus, when you worship God, give thanks for his self-attesting word and the work of his Holy Spirit.

Further Reading

This essay is part of the Concise Theology series. All views expressed in this essay are those of the author. This essay is freely available under Creative Commons License with Attribution-ShareAlike, allowing users to share it in other mediums/formats and adapt/translate the content as long as an attribution link, indication of changes, and the same Creative Commons License applies to that material. If you are interested in translating our content or are interested in joining our community of translators, please reach out to us.

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