Ver. 1. That ye sin not] Presuming upon an easy and speedy pardon. The worst sort of Papists will say, When we have sinned, we must confess; and when we have confessed, we must sin again, that we may confess again; so making account of confessing, as drunkards do of vomiting. But we have not so learned Christ. If his word dwell richly in us, it will teach us to deny ungodliness, &c.; to forsake as well as confess sin, and not after confession, to turn again to folly, or (as those that are dog sick) to their former vomit. With confession of sin must be joined confusion of sin, Proverbs 28:13. We may not do as those Philistines, that confessed their error and yet sent away the ark of God, 1 Samuel 6:3. Nor as Saul, “I have sinned, yet honour me before the people,” 1 Samuel 15:30. Nor yet as those perverse Israelites, “We have sinned, we will go up”; though God had flatly forbidden them at that time to go up against the Amorites; and for their presumptuous attempt brought them back by weeping cross, Deuteronomy 1:41-43, &c. Sin confessed must be, 1. Disallowed in our judgments. 2. Disavowed and declined in our wills and affections. 3. Cast out of our practice; Ephraim shall say, “What have I to do any more with idols?” Hosea 14:8. He shall pollute the images that he had once perfumed: he shall angrily say unto them, Get you hence, Isaiah 30:22. And if any man sin] Being taken before he is aware, Galatians 6:1. [See Trapp on “Ga 6:1”] We have an advocate] Who appears for us in heaven, and pleads our cause effectually. See Hebrews 9:24. Jesus Christ the righteous] Or else he could not go to the Father for us. [See Trapp on “Joh 16:10”]
Ver. 2. He is the propitiation] Heb. Copher; he coffers up, as it were, and covers our sins, Psalms 78:38. [See Trapp on “Ro 3:25”] The Hebrew word רפכ used for covering and propitiating of sin, is (Genesis 6:14) used of the pitch or plaster whereby the wood of the ark was so fastened that no water could get in. But also for the sins of the whole world] That is, of all the faithful, both of Jews and Gentiles, that mundus ex mundo, that world of whom the world is not worthy, Hebrews 11:38.
Ver. 3. We know that we know him] By a reflex act of the soul; hence the assurance of faith, the fruit of fruitfulness, 1 Corinthians 15:58. That we know him] With a knowledge not apprehensive only, but affective too. If we keep his commandments] Si facimus praecepta, etiamsi non perficiamus; If we think upon his commandments to do them, Psalms 103:18, aim at them, as at a mark, Psalms 119:6. “ Non semper feriet quodcunque minabitur arcus. ” Wish well to an exact obedience which yet we cannot attain to, Psalms 119:4,5; be doing at it as we can, following after righteousness, Proverbs 15:9, as a poor aprentice follows his trade, though he be nothing less than his craftmaster; and lastly, be humbled for our daily aberrations, resolving and striving to do better: this is that evangelical keeping of God’s commandments, which God (measuring the deed by the desire, and the desire by the sincerity thereof) will accept and crown, through Christ our propitiation.
Ver. 4. He that saith, I know him] Here he disputeth against Verbalists and Solifidians. See James 2:14. [See Trapp on “Jas 2:14”] Is a liar] i.e. A hypocrite; his spot is not the spot of God’s children, Deuteronomy 32:5, for they are children that will not lie, Isaiah 63:8. They all deserve that title of honour that was given of old to Arrianus the historian, viz. φιλαληθης, A lover of truth. They know that the God whom they serve, desireth “truth in the inward parts,” Psalms 51:6, and that dicta factis deficientibus erubescant (as Tertullian hath it), words without deeds will not bear a man out in the end. It is a question whether the desire of being, or dislike of seeming, sincere, be greater in the good heart. Not so every loose and ungirt Christian, every profligate professor, that denieth that in deed what he affirmeth in word.
Ver. 5. In him verily is the love of God perfected] St John was a mere compound of sweetest love. As iron put into the fire, seemeth to be nothing but fire, so he (the beloved disciple) was turned into a lump of love. Hence he so presseth love, perfect love, to God and his people. And Jerome tells us, that living to a very great age at Ephesus, he would get up into the pulpit; and when through weakness of body he could say no more, he would say, “Little children, love one another”; Si hoc solum fiat, sufficit, If this be well done, all is done. (Jerome in cap. vi. ad Gal.) That we are in him] In communion with him, and in conformity to him.
Ver. 6. To walk even as he walked] This is the same with that Colossians 2:6, to walk in Christ; and with that, 1 Peter 2:21, to follow his steps. [See Trapp on “1Pe 2:21”]
Ver. 7. I write no new commandment] The apostle studiously declineth the suspicion of novelty. We should ever set a jealous eye upon that which is new, and stand in the old way, Jeremiah 6:16, in the ancient paths, Jeremiah 18:15. God’s people are called the ancient people, Isaiah 44:7. And idolaters are said to sacrifice to new gods, that came newly up, Deuteronomy 32:17. Truth, as wine, is better with age, Luke 5:39. And of witnesses, Aristotle well saith, the older they are, the more credible, because less corrupted, πιστοτατοι οι παλαιοι, αδιαφθοροι γαρ (Rhet. i.). As we prefer the newest philosophy, so the ancient est divinity; and we may justly suspect them of falsehood and delusions, who arrogate to themselves to utter oracles, to bring to light new truths, &c.