John 12:38

(Hom. lxviii. 2) But why then did Christ come? Did He not know that they would not believe in Him? Yes: the Prophets had prohibited this very unbelief, and He came that it might be made manifest, to their confusion and condemnation; That the saying of Esaias the prophet might be fulfilled, which He spake, Lord, who hath believed our report? and to whom hath the arm of the Lord been revealed? (Hom. lxviii. 2) That the saying of Esaias might be fulfilled: that here is expressive not of the cause, but of the event. They did not disbelieve because Esaias said they would; but because they would disbelieve, Esaias said they would.

(Tr. liii. 2) It is evident here that the arm of the Lord is the Son of God Himself. Not that the Father has a human fleshly form; He is called the arm of the Lord, because all things were made by Him. If a man had power of such a kind, as that without any motion of his body, what he said was forthwith done, the word of that man would be his arm. Here is no ground to justify, however, the error of those who say that the Godhead is one Person only, because the Son is the arm of the Father, and a man and his arm are not two persons, but one. These men do not understand, that the commonest things require to be explained often by applying language to them taken from other things in which there happens to be a likeness, [cand that, when we are upon things incomprehensible, and which cannot be described as they actually are, this is much more necessary. Thus one man calls another man, whom he makes great use of, his arm; and talks of having lost his arm, of having his arm taken away from him.]

"But though He had done so many miracles before them, yet they believed not on Him: that the saying of Isaiah the prophet might be fulfilled, which he spake, Lord, who hath believed our report and to whom hath the arm of the Lord been revealed?" Where he makes it sufficiently plain that the Son of God is Himself the arm of the Lord; not that the person of God the Father is determined by the shape of human flesh, and that the Son is attached to Him as a member of His body; but because all things were made by Him, and therefore He is designated the arm of the Lord. For as it is with thine arm that thou workest, so the Word of God is styled His arm; because by the Word He elaborated the world. For why does a man, in order to do some work, stretch forth his arm, but because the doing of it does not straightway follow his word? And if he was endowed with such pre-eminent power that what he said was done without any movement of his body, then would his word be his arm. But the Lord Jesus, the only-begotten Son of God the Father, as He is no mere member of the Father's body, so is He no mere thinkable, and audible, and transitory word; for, as all things were made by Him, He was the word of God. When, therefore, we hear that the Son of God is the arm of God the Father, let no carnal custom raise its distracting din in our ears; but as far as His grace enables us, let us think of that power and wisdom of God by which all things were made. Surely such an arm as that is neither held out by stretching, nor drawn in by contracting it. For He is not one and the same with the Father, but He and the Father are one; and as equal with the Father, He is in all respects complete, as well as the Father: so that no room is left open for the abominable error of those who assert that the Father alone exists, but according to the difference of causes is Himself sometimes called the Son, sometimes the Holy Spirit.

(Tr. liii. 2) But some mutter, and ask, What fault was it of the Jews, if it was necessary that the sayings of Esaias should be fulfilled? We answer, that God, foreseeing the future, predicted by the Prophet the unbelief of the Jews, but did not cause it. God does not compel men to sin, because He knows they will sin. He foreknows their sins, not His own. The Jews committed the sin, which He who knows all things foretold they would commit.

There are some, then, who mutter among themselves, and sometimes speak out when they can, and even break forth into turbulent debate, saying: What did the Jews do, or what fault was it of theirs, if it was a necessity "that the saying of Isaiah the prophet should be fulfilled, which he spake, Lord, who hath believed our report and to whom hath the arm of the Lord been revealed?" To whom our answer is, that the Lord, in His foreknowledge of the future, foretold by the prophet the unbelief of the Jews; He foretold it, but did not cause it. For God does not compel any one to sin simply because He knows already the future sins of men. For He foreknew sins that were theirs, not His own; sins that were referable to no one else, but to their own selves. Accordingly, if what He foreknew as theirs is not really theirs, then had He no true foreknowledge: but as His foreknowledge is infallible, it is doubtless no one else, but they themselves, whose sinfulness God foreknew, that are the sinners. The Jews, therefore, committed sin, with no compulsion to do so on His part, to whom sin is an object of displeasure; but He foretold their committing of it, because nothing is concealed from His knowledge. And accordingly, had they wished to do good instead of evil, they would not have been hindered; but in this which they were to do they were foreseen of Him who knows what every man will do, and what He is yet to render unto such an one according to his work.