Augustine of Hippo — as excerpted in the Catena Aurea on John 8:44-47

“(xi. de Civ. Dei, c. 13) But it will be objected perhaps, that if from the beginning of his existence, the devil stood not in the truth, he was never in a state of blessedness with the holy angels, refusing, as he did, to be subject to his Creator, and therefore false and deceitful; unwilling at the cost of pious subjection to hold that which by nature he was; and attempting in his pride and loftiness to simulate that which he was not. This opinion is not the same with that of the Manichæans, that the devil has his own peculiar nature, derived as it were from the opposite principle of evil. This foolish sect does not see that our Lord says not, Was alien from the truth, but Stood not in the truth, meaning, fell from the truth. And thus they interpret John, The devil sinneth from the beginning, (1 John 3:8) not seeing that if sin is natural, it is no sin. But what do the testimonies of the prophets reply? Isaiah, setting forth the devil under the figure of the prince of Babylon, says, How art thou fallen from heaven, O Lucifer, son of the morning! (Ezek. 28:13) Ezekiel says, Thou hast been in Eden, the garden of God. Which passages, as they cannot be interpreted in any other way, shew that we must take the word, He stood not in the truth, to mean, that he was in truth, but did not remain in it; and the other, that the devil sinneth from the beginning, to mean, that he was a sinner not from the beginning of his creation, but from the beginning of sin. For sin began in him, and he was the beginning of sin.”