1 John 1:8

“If we say that we have no sin, &c.] Notwithstanding believers are cleansed from their sins by the blood of Christ, yet they are not without sin; no man is without sin: this is not only true of all men, as they come into the world, being conceived in sin, and shapen in iniquity, and of all that are in a state of unregeneracy, and of God's elect, while in such a state, but even of all regenerated and sanctified persons in this life; as appears by the ingenuous confessions of sin made by the saints in all ages; by their complaints concerning it, and groans under it; by the continual war in them pardoning grace, and for the fresh application of Christ's blood for cleansing; by their frequent…”

“The confession of sins is a necessary consequence of "walking in the light" (Jo1 1:7). "If thou shalt confess thyself a sinner, the truth is in thee; for the truth is itself light. Not yet has thy life become perfectly light, as sins are still in thee, but yet thou hast already begun to be illuminated, because there is in thee confession of sins" [AUGUSTINE]. that we have no sin--"HAVE," not "have had," must refer not to the past sinful life while unconverted, but to the present state wherein believers have sin even still. Observe, "sin" is in the singular; "(confess our) sins" (Jo1 1:9) in the plural. Sin refers to the corruption of the old man still present in us, and the stain created by…”

“If we say that we have no sin - It is not improbable that the apostle here makes allusion to some error which was then beginning to prevail in the church. Some have supposed that the allusion is to the sect of the Nicolaitanes, and to the views which they maintained, particularly that nothing was forbidden to the children of God under the gospel, and that in the freedom conferred on Christians they were at liberty to do what they pleased, Revelation 2:6, Revelation 2:15. It is not certain, however, that the allusion is to them, and it is not necessary to suppose that there is reference to any particular sect that existed at that time. The object of the apostle is to show that it is implied…”

“If we say - Any child of man, before his blood has cleansed us. We have no sin - To be cleansed from, instead of confessing our sins, Jo1 1:9, the truth is not in us - Neither in our mouth nor in our heart. 1 John 1:9”

“1:8 If we claim we have no sin: This is the second false claim of the Gnostics (see 1:6). They claimed that they were or could be sinless since Christ had abolished their sins once and for all—their higher knowledge would lift them above the realm of sin. But Christians do still sin when they live in their old nature (see Rom 7:14-25). The true Christian both acknowledges this sin (1 Jn 1:9) and trusts in Christ to take it away.”

“say: Jo1 1:6, Jo1 1:10, Jo1 3:5, Jo1 3:6; Kg1 8:46; Ch2 6:36; Job 9:2, Job 14:4, Job 15:14, Job 25:4; Psa 143:2; Pro 20:9; Ecc 7:20; Isa 53:6, Isa 64:6; Jer 2:22, Jer 2:23; Rom 3:23; Jam 3:2 we deceive: Co1 3:18; Gal 6:3; Ti2 3:13; Jam 1:22, Jam 1:26; Pe2 2:13 the truth: Jo1 2:4; Ti1 6:5; Jo2 1:2; Jo3 1:3 1 John 1:9”