Psalms 81:5

In Isaiah: “Hear, O heaven, and give ear, O earth: for the Lord hath spoken; I have begotten and brought up children, but they have rejected me. The ox knoweth his owner, and the ass his master’s crib: but Israel hath not known me, and my people hath not perceived me. Ah sinful nation, a people filled with sins, a wicked seed, corrupting children: ye have forsaken the Lord, and have sent that Holy One of Israel into anger.” In the same also the Lord says: “Go and tell this people, Ye shall hear with the ear, and shall not understand; and seeing, ye shall see, and shall not perceive. …

In Genesis: “And God said unto Jacob, Arise, and go up to the place of Bethel, and dwell there; and make there an altar to that God who appeared unto thee when thou fleddest from the face of thy brother Esau.” Also in Isaiah: “Thus saith the Lord, the God of Sabaoth, Egypt is wearied; and the merchandise of the Ethiopians, and the tall men of the Sabeans, shall pass over unto Thee, and shall be Thy servants; and shall walk after Thee bound with chains; and shall worship Thee, and shall pray to Thee, because God is in Thee, and there is no other God beside Thee. For Thou art God, and we knew it not, O God of Israel, our Saviour. They shall all be confounded and fear who oppose Thee, and shall fall into confusion.” Likewise in the same: “The voice of one crying in the wilderness, Prepare ye the way of the Lord, make straight the paths of our God. …

“And the light shineth in darkness and the darkness hath not overtaken it.” We are still enquiring about the light of men, since it is what was spoken of in the preceding verse, and also, I consider, about darkness, which is named as its adversary, the darkness also being, if the definition of it is correct, that of men. The light of men is a generic notion covering two special things; and with the darkness of men it is the same. He who has gained the light of men and shares its beams will do the work of light and know in the higher sense, being illuminated by the light of the higher knowledge. And we must recognize the analogous case of those on the other side, and of their evil actions, and of that which is thought to be but is not really knowledge, since those who exercise it have the reason (Logos) not of light but of darkness. …

4. To all of them, verily, what follows is most fitly suited: “They did not know nor understand, they walk on in darkness” ( ver. 5 ). “For if even they had known, they would never have crucified the Lord of glory:” and those others, if they had known, would never have consented to ask that Barabbas should be freed, and Christ should be crucified. But as the above-mentioned blindness happened in part unto Israel until the fulness of the Gentiles should come in, this blindness of that People having caused the crucifixion of Christ, “all the foundations of the earth shall be moved.” So have they been moved, and shall they be moved, until the predestined fulness of the Gentiles shall come in. For at the actual death of the Lord the earth was moved, and the rocks rent. …

2. You, however, beloved and most truly longed-for, have done what befitted the tradition of the Church and your piety toward the Lord, in refuting, admonishing, and rebuking such men. But since, instigated by their father the devil, ‘they knew not nor understood,’ as it is written, ‘but go on still in darkness,’ let them learn from your piety that this error of theirs belongs to Valentinus and Marcion, and to Manichæus, of whom some substituted [the idea of] Appearance for Reality, while the others, dividing what is indivisible, denied the truth that ‘the Word was made Flesh, and dwelt among us.’ Why then, as they hold with those people, do they not also take up the heritage of their names? For it is reasonable, as they hold their error, to have their names as well, and for the future to be called Valentinians, Marcionists, and Manichæans. …

Granting that the knowledge which they believe themselves to have acquired is somewhat greater than that of others: yet can they possess more than the belief that the Son of the Very God is Very God, seeing that in that article of the Very God every idea that is orthodox, every idea that is our salvation, is included? It includes the idea of His Goodness, His Justice, His Omnipotence: that He admits of no variableness nor alteration, but is always the same; incapable of changing to worse or changing to better, because the first is not His nature, the second He does not admit of; for what can be higher than the Highest, what can be better than the Best? In fact, He is thus associated with all perfection, and, as to every form of alteration, is unalterable; He did not on occasions display this attribute, but was always so, both before the Dispensation that made Him man, and during it, and …