“If we truly want to help men’s consciences so that they are not gripped by perpetual doubt, we must derive the authority of Scripture from a higher source than human reasoning, evidence or conjecture. We must, that is, base it on the inner witness of the Holy Spirit.
Although Scripture’s own majesty is enough to command our reverence, it really begins to affect us only when it is sealed in our hearts by the Holy Spirit. Being illumined by his power, we no longer believe on the strength of our own or of others’ judgment that Scripture is from God. Above and beyond all human judgment we conclude without question that it is given to us from the mouth of God himself, through the ministry of men. It is as if, in Scripture, we beheld with our own eyes the very essence of God. We cease, therefore, to look for proofs and probabilities on which to base our judgment; instead, we subject our judgment and intellect to Scripture, as to a source so high as to rule out the need for judgment. Not because we are like some who thoughtlessly embrace unfamiliar things only to tire of them once they become better known; but because we are very sure that in Scripture we have the unassailable truth. Nor because we are like the ignorant who are in the habit of surrendering their minds to superstition; but because we feel that in Scripture the express power of deity is displayed, kindling in us the desire to give conscious and willing obedience more powerfully than if only human will or knowledge were involved.
This, then, is a conviction which does not require reasons. Nevertheless it is also a knowledge which is based upon a very sound reason, since our mind has a firmer and surer place to rest than in any set of reasons. It is, finally, a feeling which can only spring from heavenly revelations. Here I am talking of nothing else than what every believer experiences in himself, except that my words do not do justice to so worthy a theme, and are most inadequate as an explanation.
Unless we have a higher and firmer certainty than any human judgement can provide, there is no point proving the authority of Scripture by rational argument: it cannot be established on the basis of the church’s consent nor can it be confirmed by other evidences. For if this foundation is not first laid, it is bound to remain in abeyance. Once, however, we obediently accept Scripture as we should, and place it beyond all doubt, the reasons which before were not strong enough to impart certainty to our hearts will now appear as valuable aids.”
– John Calvin, The Institutes of the Christian Religion. p.20-21 (John White’s translation of 1541 version)
“The implication of what has been said is this: If Christians ask non-Christians merely to accept the gospels or some other part of Scripture as historically trustworthy documents, they are allowing the legitimacy and efficacy of the principle of autonomy. They are allowing that it is possible intelligently to identify and set in order the elements of human experience in history by means of the principle of autonomy. But if this were true, if by the principle of autonomy such identification and ordering could take place, there is no need for the idea of God speaking to men. It is just because man cannot speak intelligently to himself without God and because the sinner has sent God out of his life that God in condescending grace comes back to him. But he asks men to accept him at his word for what he is, the indispensable presupposition of all intelligent human predication.
It is in consonance with this approach that the Reformed Confessions assert that our final acceptance of the Scriptures as the Word of God rests upon the internal testimony of the Holy Spirit. All the indications of the divinity of Scripture would lose their effectiveness and would indeed accomplish the very opposite of what they are meant to accomplish if they were taken out of their relation of dependence upon the testimony of the Holy Spirit. These indications do, of course, objectively show the Scriptures to be the Word of God. The whole Bible in all respects shows itself objectively to be the Word of God. The majesty of its style, the harmony of its parts and other such things, all indicate the Scriptures to be the Word of God. Prophecies fulfilled and miracles performed, the works as well as the words of Christ, all that Scripture contains, shows its divinity. The record of these works and words of the Christ is ipso facto as a record identified by God as the Word of God. But the acceptance of both the Christ and his word, both the personal word and the spoken word, comes by virtue of one and the same act of submission and surrender. And this act of surrender and faith comes in consequence of the testimony of the Holy Spirit.
This testimony of the Holy Spirit is therefore not a new revelation of God that would in turn need a new testimony for its corroboration. Nor does it work apart from the objective evidence of the divinity of Scripture. It appeals to man as made in the image of God with full ability to see and understand the significance of his deeds. It speaks to this same man as the sinner with utter inability to understand spiritually and to respond obediently to the demands of the gospel. It speaks to him through the content of the Bible and only through the content of the Bible. It actually convinces the sinner and practically convicts him of sin and of judgment. It compels him to believe that which he knows he ought to believe but which because of the perverseness of his will and the darkness of his mind he otherwise cannot believe, namely, that the Bible is the Word of God and what it contains is the system of truth as given to man by God.”
– Cornelius Van Til, A Christian Theory of Knowledge p.228-229