Continuing from last week’s entry from Piper’s God Is the Gospel (and very much in tune with yesterday’s post on Thomas Chalmers), in which we saw that the Word of God is confirmed by none other than his own Spirit, we will now see how that happens, and how it does not. Piper writes:

The Unmistakable Majesty of God Manifest in the Word
But how does this persuasion happen? Is it by the Spirit telling us a new fact—namely, the whisper, “This book is true”? Do we hear a voice? That is not the way it happens. The glory of God in the gospel does not need another witness of that sort. How then does the internal testimony of the Spirit work in conjunction with the glory of God in the gospel? What does the Spirit do?
   The answer is not that the Spirit gives us added revelation to what is in Scripture, but that he awakens us, as from the dead, to see and taste the divine reality of the glory of Christ in the gospel. (Recall the seeing of 2 Corinthians 4:4, 6.) This sight authenticates the gospel as God’s own Word. Calvin says, “Our Heavenly Father, revealing his majesty [in the gospel], lifts reverence for Scripture above the realm of controversy” [Institutes, 1:92 (I.vi.13).]. This is the key for Calvin: the witness of the gospel is the immediate, unassailable, life-giving revelation to the mind of the majesty of od manifest in the Word itself—not in new revelation about it.
   We are almost at the bottom of this experience of the internal testimony of the Spirit. Here are the words that will take us deeper.

Therefore illumined by [the Spirit’s] power, we believe neither by our own [note this!] 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. [John Calvin, Institutes of the Christian Religion (Westminster Press, 1960), 1:80 (I.vii.5).]

—John Piper, God Is the Gospel (Crossway, 2005), 79.