"If we say we have no sin, we deceive ourselves, and the truth is not in us." (1 John 1:8 KJV)
I wish you to notice the connection in which these words stand. The connection is this: "If we walk in the light as He is in the light, we have fellowship one with another, and the blood of Jesus Christ His Son cleanseth us from all sin. If we say that we have no sin, . . . the truth is not in us. But if we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness."
Now if the "we" here means the persons cleansed, just spoken of when it says, "The blood of Jesus Christ cleanseth us from all sin," we must convict this inspired writer of a manifest contradiction in affirming that the same persons are cleansed from all sin and yet are still living in sin. It is very much like saying that vaccination is a prophylactic against small-pox, but if any one tries it, and proves it is so, he is a liar. Or quinine is a specific against fevers, especially malarial fevers, but if any one tries it, and is cured, and makes declaration of the fact, it is false. That is the absurdity to which John is reduced by that kind of exposition.