But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus Christ, his Son, cleanses us from all sin.
By saying, from all sin, he intimates that we are, on many accounts, guilty before God; so that doubtless there is no one who has not many vices. But he shews that no sins prevent the godly, and those who fear God, from obtaining his favor. He also points out the manner of obtaining pardon, and the cause of our cleansing, even because Christ expiated our sins by his blood; but he affirms that all the godly are undoubtedly partakers of this cleansing. 