Look at it like this. When the Christ drank His Father's most bitter cup[see Psalms 75:8], He ingested His sheep's sins. He who knew no sins, BECAME sin for us. He is forever the sinless Lamb of God, yet He stood before His Father as if He had committed every sin of every elect had ever committed. He bore this wrath for them, dying their death for them. He was sinless, yet at the cross, God saw Him as a sinner.
Now that He did that, His sheep can now stand before the Father clothed in His Son's righteousness, as if they never sinned a day in their life. It's not that we don't see, because we do, but that God sees us through His Son. He sees us sinless in the Christ.
Until you get the cross right, none of these questions you ask will be answered correctly and you agree with them.
I know you believe that and it is straight out of the Reformation, so its been around for a long time. It seems right to you, but it is dead wrong. It is the Holy Spirit that is seldom mentioned except in passing in your circles, that empowers us to no longer sin.
Your verse 1 John 1:8 is in context with 1 John 1:9. Since Adam, all have sinned and fallen short of the glory of God. That is 1 John 1:8 in John's words. To BECOME a Christian you must do verse 9. Verse 8 is BEFORE Christ.
Romans 8:38-39 doesn't mention sin, the one thing that can separate us from God, just like it did Adam and Eve.
1 John 3:5-9
4 Whoever commits sin also commits lawlessness, and sin is lawlessness. 5 And you know that He was manifested to take away our sins, and in Him there is no sin. 6 Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him.
7 Little children, let no one deceive you. He who practices righteousness is righteous, just as He is righteous. 8 He who sins is of the devil, for the devil has sinned from the beginning. For this purpose the Son of God was manifested, that He might destroy the works of the devil. 9 Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God.
Romans 8:1-9
There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit. 2 For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death. 3 For what the law could not do in that it was weak through the flesh, God
did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh, 4 that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit. 5 For those who live according to the flesh set their minds on the things of the flesh, but those
who live according to the Spirit, the things of the Spirit. 6 For to be carnally minded
is death, but to be spiritually minded
is life and peace. 7 Because the carnal mind
is enmity against God; for it is not subject to the law of God, nor indeed can be. 8 So then, those who are in the flesh cannot please God.
9 But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His.