John 3:14

After having spoken of the very great benefaction that had come to man by Baptism, He proceeds to mention another benefaction, which was the cause of this, and not inferior to it; namely, that by the Cross. As also Paul arguing with the Corinthians sets down these benefits together, when he says, "Was Paul crucified for you? or were ye baptized into the name of Paul?" for these two things most of all declare His unspeakable love, that He both suffered for His enemies, and that having died for His enemies, He freely gave to them by Baptism entire remission of their sins. But wherefore did He not say plainly, "I am about to be crucified," instead of referring His hearers to the ancient type? First, that you may learn that old things are akin to new, and that the one are not alien to the other; next, that you may know that He came not unwillingly to His Passion; and again, besides these reasons, that you may learn that no harm arises to Him from the Fact, and that to many there springs from it salvation. For, that none may say, "And how is it possible that they who believe on one crucified should be saved, when he himself is holden of death?" He leads us to the ancient story. Now if the Jews, by looking to the brazen image of a serpent, escaped death, much rather will they who believe on the Crucified, with good reason enjoy a far greater benefit. For this takes place, not through the weakness of the Crucified, or because the Jews are stronger than He, but because "God loved the world," therefore is His living Temple fastened to the Cross.

(de Pecc. mer. et remiss. c. xxxii) Many dying in the wilderness from the attack of the serpents, Moses, by commandment of the Lord, lifted up a brazen serpent: and those who looked upon it were immediately healed. The lifting up of the serpent is the death of Christ; the cause, by a certain mode of construction, being put for the effect. The serpent was the cause of death, inasmuch as he persuaded man into that sin, by which he merited death. Our Lord, however, did not transfer sin, i. e. the poison of the serpent, to his flesh, but death; in order that in the likeness of sinful flesh, there might be punishment without sin, by virtue of which sinful flesh might be delivered both from punishment and from sin. (Tr. xii. c. 11) As then formerly he who looked to the serpent that was lifted up, was healed of its poison, and saved from death; so now he who is conformed to the likeness of Christ's death by faith and the grace of baptism, is delivered both from sin by justification, and from death by the resurrection: as He Himself saith; That whosoever believeth on Him should not perish, but have everlasting life. What need then is there that the child should be conformed by baptism to the death of Christ, if he be not altogether tainted by the poisonous bite of the serpent? (Tr. xii. c. 11) But there is this difference between the figure and the reality, that the one recovered from temporal death, the other from eternal.

He endured death, then; but death He hanged on the cross, and mortal men are delivered from death. The Lord calls to mind a great matter, which was done in a figure with them of old: "And as Moses," saith He, "lifted up the serpent in the wilderness, so must the Son of man be lifted up; that every one who believeth on Him may not perish, but have everlasting life." A great mystery is here, as they who read know. Again, let them hear, as well they who have not read as they who have forgotten what perhaps they had heard or read. The people Israel were fallen helplessly in the wilderness by the bite of serpents; they suffered a great calamity by many deaths: for it was the stroke of God correcting and scourging them that He might instruct them. In this was shown a great mystery, the figure of a thing to come: the Lord Himself testifies in this passage, so that no man can give another interpretation than that which the truth indicates concerning itself. Now Moses was ordered by the Lord to make a brazen serpent, and to raise it on a pole in the wilderness, and to admonish the people Israel, that, when any had been bitten by a serpent, he should look to that serpent raised up on the pole. This was done: men were bitten; they looked and were healed. What are the biting serpents? Sins, from the mortality of the flesh. What is the serpent lifted up? The Lord's death on the cross. For as death came by the serpent, it was figured by the image of a serpent. The serpent's bite was deadly, the Lord's death is life-giving. A serpent is gazed on that the serpent may have no power. What is this? A death is gazed on, that death may have no power. But whose death? The death of life: if it may be said, the death of life; ay, for it may be said, but said wonderfully. But should it not be spoken, seeing it was a thing to be done? Shall I hesitate to utter that which the Lord has deigned to do for me? Is not Christ the life? And yet Christ hung on the cross. Is not Christ life? And yet Christ was dead. But in Christ's death, death died. Life dead slew death; the fullness of life swallowed up death; death was absorbed in the body of Christ. So also shall we say in the resurrection, when now triumphant we shall sing, "Where, O death, is thy contest? Where, O death, is thy sting?" Meanwhile brethren, that we may be healed from sin, let us now gaze on Christ crucified; for "as Moses," saith He, "lifted up the serpent in the wilderness, so must the Son of man be lifted up; that whosoever believeth on Him may not perish, but have everlasting life." Just as they who looked on that serpent perished not by the serpent's bites, so they who look in faith on Christ's death are healed from the bites of sins. But those were healed from death to temporal life; whilst here He saith, "that they may have everlasting life." Now there is this difference between the figurative image and the real thing: the figure procured temporal life; the reality, of which that was the figure, procures eternal life.

He introduces the teacher of the Mosaic law, to the spiritual sense of that law; by a passage from the Old Testament history, which was intended to be a figure of His Passion, and of man's salvation.

(in loc.) See then the aptness of the figure. The figure of the serpent has the appearance of the beast, but not its poison: in the same way Christ came in the likeness of sinful flesh, being free from sin. By Christ's being lifted up, understand His being suspended on high, by which suspension He sanctified the air, even as He had sanctified the earth by walking upon it. Herein too is typified the glory of Christ: for the height of the cross was made His glory: for in that He submitted to be judged, He judged the prince of this world; for Adam died justly, because he sinned; our Lord unjustly, because He did no sin. So He overcame him, who delivered Him over to death, and thus delivered Adam from death. And in this the devil found himself vanquished, that he could not upon the cross torment our Lord into hating His murderers: but only made Him love and pray for them the more. In this way the cross of Christ was made His lifting up, and glory.