(I decided to stay home from church today, so as not to get all the children sick.)

“Fear not, for I am with thee; I will bring thy seed from the east, and gather thee from the west.
I will say to the north, Give up; and to the south, Keep not back;
           Bring my sons from far, and my daughters from the ends of the earth.
Even every one that is called by name:
           For I have created him for my glory;
                I have formed him;
           Yea, I have made him.
Bring forth the blind people that have eyes, and the deaf that have ears.
Let all the nations be gathered together, and let the people be assembled:
           Who among them can declare this, and show us former things?
           Let them bring forth their witnesses, that they may be justified –
                    Or let them hear, and say, It is truth.
Ye are my witnesses, saith the Lord, and my servant whom I have chosen:
           That ye may know and believe me, and understand that I am he:
           Before me there was no god formed,
                     Neither shall there be after me.
I, even I, am the Lord;
           And beside me there is no savior.
I have declared, and have saved, and I have showed, when there was no strange god among you:
           Therefore ye are my witnesses, saith the Lord, that I am God.
Yea, before the day was, I am he;
           And there is none that can deliver out of my hand;
           I will work, and who shall let [hinder] it?”                                 Isaiah 43: 5-13

From Calvin’s Institutes of the Christian Religion, book 1, chapter 7, second half of the chapter (emphasis added):

Yet they who strive to build up firm fatih in Scripture through disputation are doing things backwards. . . . [E]ven if anyone clears God’s Sacred Word from man’s evil speaking, he will not at once imprint upon their hearts that certainty which piety requires. Since for unbelieving men religion seems to stand by opinion alone, they, in order not to believe anything foolishly or lightly, both wish and demand rational proof that Moses and the prophets spoke divinely.

But I reply: the testimony of the Spirit is more excellent than all reason. For as God alone is a fit witness of himself in his Word, so also the Word will not find acceptance in men’s hearts before it is sealed by the inward testimony of the Spirit. The same Spirit, therefore, who has spoken through the mouths of the prophets must penetrate into our hearts to persuade us that they faithfully proclaimed what had been divinely commanded. Isaiah very aptly expresses this connection in these words: “My Spirit which is in you, and the words that I have put in your mouth, and the mouths of your offspring, shall never fail.” [Is. 59:21]

. . .  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; hence, it is not right to subject it to proof and reasoning. And the certainty it deserves with us, it attains by the testimony of the Spirit. For even if it wins reverence for itself by its own majesty, it seriously affects us only when it is sealed upon our hearts through the Spirit.

Therefore, 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. We seek no proofs, no marks of genuineness upon which our judgment may lean; but we subject our judgment and wit to it as to a thing far beyond any guesswork! This we do, not as persons accustomed to seize upon some unknown thing, which, under closer scrutiny, displeases them, but fully conscious that we hold the unassailable truth!  

. . . By this power we are drawn and inflamed, knowingly and willingly, to obey him, yet also more vitally and more effectively than by mere human willing or knowing.

God, therefore, very rightly proclaims through Isaiah that the prophets together with the whole people are witness to him; for they, instructed by prophecies, unhesitatingly held that God has spoken without deceit or ambiguity. Such, then, is a conviction that requires no reasons; such, a knowledge with which the best reason agrees – in which the mind truly reposes more securely and constantly than in any reasons; such, finally, a feeling that can be born only of heavenly revelation.