Since those marvellous works which from the days of Moses were shown to the children of Israel are attributed to Christ, it follows that He must have existed long before His birth in time.
And when the Apostle wanted to make this clear and patent to everybody he spoke as follows, saying that, “Jesus having saved the people out of the land of Egypt afterward destroyed them that believed not.” 2520 But elsewhere too we read: “Neither let us tempt Christ, as some p. 587 of them tempted, and were destroyed by serpents.” 2521 Peter also the chief of the apostles says: “And now why tempt ye God to put a yoke upon the neck of the disciples, which neither our fathers nor we have been able to bear. But we believe that we shall be saved by the grace of our Lord Jesus Christ even as they were.” 2522 We know most certainly that the people of God were delivered from Egypt, and led dryshod through mighty tracts of water, and preserved in the vast desert wastes, by none but God alone; as it is written: “The Lord alone did lead them, and there was no strange God among them.” 2523 And how can an Apostle declare in so many and such clear passages that the people of the Jews were delivered from Egypt by Jesus, and that Christ was at that time tempted by the Jews in the wilderness, saying, “Neither let us tempt Christ, as some of them tempted, and were destroyed of the serpents?” And further the blessed Apostle Peter says of all the saints who lived under the law of the Old Covenant that they were saved by the grace of our Lord Jesus Christ. Get out then, and wriggle out of this if you can—whoever you are—you who rage with vapid mouth and a spirit of blasphemy, and think that there is no difference at all between Adam and Christ; and you who deny that He was God before His birth of the Virgin, show clearly how you can prove that He was not God before His body came into existence. For lo, an Apostle says that the people were saved out of the land of Egypt by Jesus: and that Christ was tempted by unbelievers in the wilderness: and that our fathers, i.e., the patriarchs and prophets, were saved by the grace of our Lord Jesus Christ. Deny it if you can. I shall not be surprised if you manage to deny what we all read, as you have already denied what we all believe. Know then that even then it was Christ in God who led the people out of Egypt, and it was Christ in God who was tempted by the people who tempted, and it was Christ in God who saved all the righteous men by His lavish grace: for through the oneness of the mystery (of the Incarnation) the terms God and Christ so pass into each other, that whatever God did, that we may say that Christ did; and whatever afterwards Christ bore, we may say that God bore. And so when the prophet said, “There shall no new God be in thee, neither shalt thou worship any other God,” 2524 he announced it with the same meaning and in the same spirit as that with which the Apostle said that Christ was the leader of the people of Israel out of Egypt; to show that He who was born of the Virgin as man, was even through the unity of the mystery still in God. Otherwise, unless we believe this, we must either believe with the heretics that Christ is not God, or against the teaching of the prophet hold that He is a new God. But may it be far from the Catholic people of God, to seem either to differ from the prophet or to agree with heretics: or perchance the people who should be blessed may be involved in a curse, and be charged with putting their hope in man. For whoever declares that the Lord Jesus Christ was at His birth a mere man, is doubly liable to the curse, whether he believes in Him or not. For if he believes, “Cursed is he who puts his hope in man.” 2525 But if he does not believe, nonetheless is he still cursed, because though not believing in man, he still has altogether denied God.
1 Cor. x. 9.587:2522
Acts 15:10, 11.587:2523
Deut. xxxii. 12.587:2524
Jer. xvii. 5.