2 Corinthians 1:19

Is our word, then, born of our knowledge only? Do we not say many things also that we do not know? And say them not with doubt, but thinking them to be true; while if perchance they are true in respect to the things themselves of which we speak, they are yet not true in respect to our word, because a word is not true unless it is born of a thing that is known. In this sense, then, our word is false, not when we lie, but when we are deceived. And when we doubt, our word is not yet of the thing of which we doubt, but it is a word concerning the doubt itself. For although we do not know whether that is true of which we doubt, yet we do know that we doubt; and hence, when we say we doubt, we say a word that is true, for we say what we know. …

7. Augustin replied: If you allow, in consideration of the authority of the Gospel, that Christ said that He came not to destroy the law and the prophets, but to fulfill them, you should show the same consideration to the authority of the apostle, when he says, "All these things were our examples;" and again of Christ, "He was not yea and nay, but in Him was yea; for all the promises of God are in Him yea;" that is, they are set forth and fulfilled in Him. In this way you will see in the clearest light both what law Christ fulfilled, and how He fulfilled it. It is a vain attempt that you make to escape by your three kinds of law and your three kinds of prophets. It is quite plain, and the New Testament leaves no doubt on the matter, what law and what prophets Christ came not to destroy, but to fulfill. The law given by Moses is that which by Jesus Christ became grace and truth. …

8. But to the perils of tempests are added also the errors of heretics; and there are not wanting those who so try the minds of them that are in the ship, as to say that Christ was not born of a Virgin, nor had a real body, but seemed to the eyes what He was not. And these opinions of heretics have sprung up now, when the Name of Christ is already glorified throughout all nations; when Christ, that is, is as it were now walking on the sea. The disciples in their trial said, “It is a phantom.” But He giveth us strength against these pestilent opinions by His own voice, “Be of good cheer, it is I; be not afraid.” For men in vain fear have conceived these opinions concerning Christ, looking at his Honour and Majesty; and they think that He could not be so born, who hath deserved to be so Glorified, fearing Him as it were “walking on the sea.” For by this action the excellency of His honour …

Ver. 19 . “For the Son of God,” saith he, “Who was preached among you by us, even by me, and Silvanus, and Timothy, was not yea and nay.” For on this account he brings before them the company of the teachers also, as thence too giving credibility to the testimony by those who taught, and not who heard it only. And yet they were disciples; however in his modesty he counts them as in the rank of teachers. But what is, “was not yea and nay?” I have never, he saith, unsaid what before I said in the Preaching. My discourse to you was not now this, now that. For this is not of faith, but of an erring mind. “But in Him was the yea.” That is, just as I said, the word abideth unshaken and steadfast.”

25. Christ therefore is, and always is; for He, Who is, always is. And Christ always is, of Whom Moses says: “He that is hath sent me.” Gabriel indeed was, Raphael was, the angels were; but they who sometime have not been are by no means with equal reason said always to be. But Christ, as we read, “was not it is, and, it is not, but, it is was in Him.” Wherefore it is the property of God alone to be, Who ever is.