I suggest you misunderstand 1 John 1:9 Verses 1 through 3 tell us those points being revealed are the objects of the teaching not the subject. (see
footnote a ). Which means, this is a teaching to those who are not yet in Christ and are therein sinners who sin and as such are condemned. 5.
Now[l] this is the gospel[m] message[n] we have heard from him[o] and announce to you: God is light, and in him there is no darkness at all.[p] 6 If we say we have fellowship with him and yet keep on walking[q] in the darkness, we are lying and not practicing[r] the truth.
My little children, I am writing these things to you so that you may not sin.
But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous. 1 John 2:1
7But if we walk in the light, as He is in the light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin.
8If we say we have no sin, we deceive ourselves, and the truth is not in us.
9If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
10If we say we have not sinned, we make him a liar, and his word is not in us.
No one born of God
makes a practice of sinning, for God’s seed abides in him; and he cannot
keep on sinning, because he has been born of God. 1 John 3:9
We know that everyone who has been born of God
does not keep on sinning, but he who was born of God protects him, and the evil one does not touch him. 1 John 5:18
There is a difference between sinning once / falling into sin opposed to persisting in sin as noted above. We are fully able to sin after being born again which is why 1 John 1:9 was written.