How can average people, with no scholarly training, and little time to invest in historical studies, know for sure that God has spoken in the Bible?

Historically and biblically, one answer that has been given is: “the internal testimony of the Spirit.” What is it? Let’s consider John Calvin’s use of the term, and the Westminster Confession of Faith, and then test these thoughts with the Scriptures themselves.

The Sight of Glory

John Calvin described his conversion to Christ as a work of God that gave him a taste of godliness.

God, by a sudden conversion, subdued and brought my mind to a teachable frame. . . . Having thus received some taste and knowledge of true godliness, I was immediately inflamed with [an] intense desire to make progress. (John Dillenberger, John Calvin: Selections from His Writings, [Scholars Press, 1975], 26)

This experience set the direction of his understanding about how a person is persuaded that God has spoken in Scripture.

The testimony of the Spirit is more excellent than all reason. For as God alone is a fit witness of himself in his Word, the Word will not find acceptance in men’s hearts before it is sealed by the inward testimony of the Spirit. (Institutes, 1.7.4)

The testimony is not contrary to reason, but it is above reason, and communicates a greater certainty than human reasoning — even our own.

Illumined by his power, we believe neither by our own nor by anyone else’s judgment that Scripture is from God; but above human judgment we affirm with utter certainty (just as if we were gazing upon the majesty of God himself) that it has flowed to us from the very mouth of God by the ministry of men. (1.7.4)

This is remarkable: not by our own “judgment” do we believe that Scripture is from God. What does that mean? Must I not form judgments about such things? Yes, but beneath a spiritually effective judgment is a Spirit-given illumination of the “majesty of God himself.” The sight of God’s glory precedes and grounds the formation of rational judgments about its truth.

Scripture’s Self-Testimony

When Calvin says that our certainty about the Scriptures comes from a sight “as if” we were gazing upon the majesty of God himself, the “as if” is simply meant to distinguish the “gazing upon the majesty of God himself” from gazing upon the majesty of God in Scripture. We really do see the majesty of God with the eyes of the heart (Ephesians 1:18); but we see it in the Scripture, not as if in the unmediated presence of God.

Calvin: “The testimony of the Spirit is more excellent than all reason.”

Thus the internal testimony of the Spirit is not an added revelation to what we see in Scripture. It is not the voice of the Spirit saying to our unperceiving mind, “What you are now looking at in the Bible is the majesty of God; so start seeing it.” Seeing doesn’t work that way. You can’t see what you don’t see. And if you see, you don’t need to be told to see.

So, even though the term “testimony of the Spirit” can mislead in suggesting added information to what we have in the Scripture, Calvin meant that the work of the Spirit was to open the eyes of our hearts to see the majesty of God in the Scriptures. In this sense, then — though it sounds paradoxical — the “testimony of the Spirit” is the work of God to enable the self-testimony of the Scripture. “Let this point therefore stand: that those whom the Holy Spirit has inwardly taught truly rest upon Scripture, and that Scripture indeed is self-authenticated” (I, vii, 4).

The Westminster Confession put it like this:

The . . . incomparable excellencies, and the entire perfection [of the Scriptures], are arguments whereby it does abundantly evidence itself to be the Word of God: yet notwithstanding, 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. (Article 1.5)

The testimony of the Spirit is “by and with” the word. I am not sure what “with” is supposed to add to “by” in this phrase. But the focus, as with Calvin, is not on added information, but on how the Spirit enables us to see what the Scripture reveals in itself.

He Makes Us Alive

Turn now to the key passage of Scripture concerning the testimony of the Spirit.

And the Spirit is the one who testifies, because the Spirit is the truth. . . . If we receive the testimony of men, the testimony of God [= the Spirit] is greater, for this is the testimony of God that he has borne concerning his Son. . . . This is the testimony, that God gave us eternal life, and this life is in his Son. (1 John 5:6, 9, 11)

“The Spirit is the one who testifies.” This is the “testimony of God.” And it is “greater” than any human testimony — including, I think John would say in this context, the testimony of our own judgment. And what is that testimony of God? It is not merely a word delivered to our judgment for reflection, for then our conviction would rely on that reflection. What is it then?

“We are blind to spiritual majesty — until the Spirit makes us see.”

Verse 11 is the key: “This is the testimony, that God gave us eternal life.” I take that to mean that God testifies to us of his reality and the reality of his Son and his word by giving us life from the dead so that we come alive to his majesty and see him for who he is in his word. In that instant we do not reason from premises to conclusions; we see light because we are awake, and there is no prior human judgment that persuades us we are alive and awake and seeing. God’s testimony to his word is life from the dead that immediately sees.

We were dead and blind to spiritual majesty. Then the Spirit “testifies.” He makes us alive. He gives us life. “This is the testimony, that God gave us eternal life.” When Lazarus wakened in the tomb by the call, or the “testimony” of Christ, he knew, without a process of reasoning, that he was alive, because he heard the majestic word.

Seeing What’s Really There

Similarly, according to Paul, we were all blinded to the glory of Christ in the gospel. What needed to happen for us to see this self-authenticating “light of the gospel of the glory of Christ” (2 Corinthians 4:4)? What needed to happen was the work of God described in verse 6: “For God, who said, ‘Let light shine out of darkness,’ has shone in our hearts to give the light of the knowledge of the glory of God in the face of Jesus Christ” (2 Corinthians 4:6). God’s word of creation — his word of testimony! — brought life and light to our souls. We saw — in the word — “the light of the knowledge of the glory of God.”

That is the “internal testimony of the Spirit.” The word has its own glory: the glory of God in Christ with all its traces. And that glory convinces us when, by the work of the Spirit, we are granted to see what is really there.