If we are not aware of something, it is not a stumble-sin.Thank goodness as children of God we can receive forgiveness of sin, if we should stumble, being ignorant of God’s word as newly born again child of God.
New Christians walk in the light, "He that loveth his brother abideth in the light, and there is none occasion of stumbling in him." (1 John 2:10)
Thank God sinners have a way to be washed of ALL their sins by the blood of Christ. (1 John 1:7)If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say that we have not sinned, we make Him a liar, and His word is not in us.
1 John 1:9-1
Then they too can start walking in the light...which is God. (1 John 1:5)
Then they can say they have no sin.
It is those who walk in the darkness who cannot say they have no sin. Darkness is sin. (Pro 4:19)
They can't say they have fellowship with God either. (1 John 1:6)