When I say 1 John 1:8 is NOT about a true Christian, I've been called a heretic. So let's see.
7 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. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
So do we still have sin if the blood of Jesus cleanses us from all sin? Just how weak do they believe the blood of Jesus is? Is sin cleansed today, and back tomorrow??? How many times does Jesus have to die for the same sin?
Since Adam, all have sinned and fallen short of the glory of God. But don't you see that is only until that sin is cleansed, never to come back. So all of our past sins are forgiven.
That leaves present and future sins to deal with. What is different between those under the law and those under grace is that grace is now power to no longer sin, whereas those under the law had no such power, only their weak carnal nature. We walk in the Spirit; therefore, that power of God IN us helps us to not desire the sin of the old nature that is now dead, and made new in Christ. Those without this new nature under the control of the Holy Spirit do not belong to Christ, because they are still choosing darkness over the light.
The Holy Spirit's power in us is why John says in 1 John 3:9 a Christian CANNOT sin. Why, because God doesn't sin.
I'm sorry to say that those who call me a heretic for pointing out this truth, are those who know they do not have any power over sin, and want to stand on 1 John 1:8 and Romans 7 to justify their weakness to choose darkness; both of which are those BEFORE Christ.