2 This would be a real difficulty and one for ever incapable of solution were it not solved by the witness of John himself, who immediately goes on to say, “My little children, guard yourselves from idols.” If everyone that is born of God sins not, and cannot be tempted by the devil, how is it that he bids them beware of temptation? Again in the same Epistle we read: “If we say that we have no sins, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
If we say that we have not sinned, we make him a liar, and his word is not in us.” I suppose that John was baptized and was writing to the baptized: I imagine too that all sin is of the devil. Now John confesses himself a sinner, and hopes for forgiveness of sins after baptism. My friend Jovinianus says, “Touch me not, for I am clean.” What then? Does the Apostle contradict himself? By no means. In the same passage he gives his reason for thus speaking: “My little children, these things write I unto you, that you may not sin.
But if any man sin, we have an advocate with the Father, Jesus Christ the righteous: and he is the propitiation for our sins; and not for ours only, but also for the whole world. And hereby know we that we know him, if we keep his commandments. He that says, I know him, and keeps not his commandments, is a liar, and the truth is not in him. But whoso keeps his word, in him verily has the love of God been perfected. Hereby know we that we are in him: he that says he abides in him ought himself also to walk even as he walked.”
My reason for telling you, little children, that everyone who is born of God sins not, is that you may not sin, and that you may know that so long as you sin not you abide in the birth which God has given you. Yea, they who abide in that birth cannot sin. “For what communion has light with darkness? Or Christ with Belial?” As day is distinct from night, so righteousness and unrighteousness, sin and good works, Christ and Antichrist cannot blend. If we give Christ a lodging-place in our hearts, we banish the devil from thence.
If we sin and the devil enter through the gate of sin, Christ will immediately withdraw. Hence David after sinning says: “Restore unto me the joy of your salvation,” that is, the joy which he had lost by sinning. “He who says, I know him, and keeps not his commandments, is a liar, and the truth is not in him.” Christ is called the truth: “I am the way, the truth, and the life.” In vain do we make our boast in him whose commandments we keep not. To him that knows what is good, and does it not, it is sin. “As the body apart from the spirit is dead, even so faith apart from works is dead.”
And we must not think it a great matter to know the only God, when even devils believe and tremble. “He that says he abides in him ought himself also to walk even as he walked.” Our opponent may choose whichever of the two he likes; we give him his choice. Does he abide in Christ, or not? If he abide, let him then walk as Christ walked. But if there is rashness in professing to copy the virtues of our Lord, he does not abide in Christ, for he does not walk as did Christ. “He did not sin, neither was guile found in his mouth: when he was reviled, he reviled not again, and as a lamb is dumb before its shearer, so opened he not his mouth.”
To Him came the prince of this world, and found nothing in Him: although He had done no sin, God made Him sin for us. But we, according to the Epistle of James, “all stumble in many things,” and “no one is pure from sin, no not if his life be but a day long.” For who will boast “that he has a clean heart? Or who will be sure that he is pure from sin?” And we are held guilty after the similitude of Adam's transgression. Hence David says, “Behold, I was shapen in iniquity, and in sin did my mother conceive me.”
And the blessed Job, “Though I be righteous my mouth will speak wickedness, and though I be perfect, I shall be found perverse. If I wash myself with snow water and make my hands never so clean, yet will you plunge me in the ditch and my own clothes shall abhor me.” But that we may not utterly despair and think that if we sin after baptism we cannot be saved, he immediately checks the tendency: “And if any man sin, we have an advocate with the Father, Jesus Christ the righteous, and he is the propitiation for our sins.
And not for ours only, but also for the whole world.” He addresses this to baptized believers, and he promises them the Lord as an advocate for their offenses. He does not say: If you fall into sin, you have an advocate with the Father, Christ, and He is the propitiation for your sins: you might then say that he was addressing those whose baptism had been destitute of the true faith: but what he says is this, “We have an advocate with the Father, Jesus Christ, and he is the propitiation for our sins.”
And not only for the sins of John and his contemporaries, but for those of the whole world. Now in “the whole world” are included apostles and all the faithful, and a clear proof is established that sin after baptism is possible. It is useless for us to have an advocate Jesus Christ, if sin be impossible.
Source: Against Jovinianus (New Advent)