From the Epistle also of John they forthwith cull (a proof). It is said: “The blood of His Son purifieth us utterly from every sin.” Always then, and in every form, we will sin, if always and from every sin He utterly purifies us; or else, if not always, not again after believing; and if not from sin, not again from fornication. But what is the point whence (John) has started? He had predicated “God” to be “Light,” and that “darkness is not in Him,” and that “we lie if we say that we have communion with Him, and walk in darkness.” “If, however,” he says, “we walk in the light, we shall have communion with Him, and the blood of Jesus Christ our Lord purifieth us utterly from every sin.” Walking, then, in the light, do we sin? and, sinning in the light, shall we be utterly purified? By no means. For he who sins is not in the light, but in darkness. Whence, too, he points out the mode in which we shall be utterly purified from sin—(by) “walking in the light,” in which sin cannot be committed. Accordingly, the sense in which he says we “are utterly purified” is, not in so far as we sin, but in so far as we do not sin. For, “walking in the light,” but not having communion with darkness, we shall act as they that are “utterly purified;” sin not being quite laid down, but not being wittingly committed. For this is the virtue of the Lord’s blood, that such as it has already purified from sin, and thenceforward has set “in the light,” it renders thenceforward pure, if they shall continue to persevere walking in the light. “But he subjoins,” you say, “If we say that we have not sin, we are seducing ourselves, and the truth is not in us. If we confess our sins, faithful and just is He to remit them to us, and utterly purify us from every unrighteousness.” Does he say “from impurity?” (No): or else, if that is so, then (He “utterly purifies” us) from “idolatry” too. But there is a difference in the sense. For see yet again: “If we say,” he says, “that we have not sinned, we make Him a liar, and His word is not in us.” All the more fully: “Little children, these things have I written to you, lest ye sin; and if ye shall have sinned, an Advocate we have with God the Father, Jesus Christ the righteous; and, He is the propitiation for our sins.” “According to these words,” you say, “it will be admitted both that we sin, and that we have pardon.” What, then, will become (of your theory), when, proceeding (with the Epistle), I find something different? For he affirms that we do not sin at all; and to this end he treats at large, that he may make no such concession; setting forth that sins have been once for all deleted by Christ, not subsequently to obtain pardon; in which statement the sense requires us (to apply the statement) to an admonition to chastity. “Every one,” he says, “who hath this hope, maketh himself chaste, because He too is chaste. Every one who doeth sin, doeth withal iniquity; and sin is iniquity. And ye know that He hath been manifested to take away sins”—henceforth, of course, to be no more incurred, if it is true, (as it is,) that he subjoins, “Every one who abideth in Him sinneth not; every one who sinneth neither hath seen nor knoweth Him. Little children, let none seduce you. Every one who doeth righteousness is righteous, as He withal is righteous. He who doeth sin is of the devil, inasmuch as the devil sinneth from the beginning. For unto this end was manifested the Son of God, to undo the works of the devil:” for He has “undone” them withal, by setting man free through baptism, the “handwriting of death” having been “made a gift of” to him: and accordingly, “he who is being born of God doeth not sin, because the seed of God abideth in him; and he cannot sin, because he hath been born of God. Herein are manifest the sons of God and the sons of the devil.” Wherein? except it be (thus): the former by not sinning, from the time that they were born from God; the latter by sinning, because they are from the devil, just as if they never were born from God? But if he says, “He who is not righteous is not of God,” how shall he who is not modest again become (a son) of God, who has already ceased to be so?