Well, I just recently addressed Romans 3. Romans 3:23 has to be read in context. Unless of course you believe no believer seeks after God and or no believer understands His ways (Romans 3:11).
Romans 3:10 As it is written: "There is none righteous, no, not one; 11 There is none who understands; There is none who seeks after God. 12 They have all turned aside; They have together become unprofitable; There is none who does good, no, not one." Romans 3:18 "There is no fear of God before their eyes." 19 Now we know that whatever the law says, it says to those who are under the law, that every mouth may be stopped, and all the world may become guilty before God. Descriptive of believers? 20 Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin. 21 But now the righteousness of God apart from the law is revealed, being witnessed by the Law and the Prophets, 22 even the righteousness of God, through faith in Jesus Christ, to all and on all who believe. For there is no difference; 23 for all have sinned and fall short of the glory of God, 24 being justified freely by His grace through the redemption that is in Christ Jesus. Is Paul saying that believers don't seek after God and don't understand His ways or unbelievers?
As for 1 John 1:8 and 1 John 1:10. It does not say anything about a general confession of sin here.
Verse 9 if we confess our sins is IN CONTRAST TO if we say we have no sin (vs. 8) and if we say we have not sinned (vs. 10). This is ongoing and not a one time temporary event.
1 John 2:1 refutes that type of thinking. John says we are to sin not. Meaning any kind of sin. But if we do sin. Still talking about one sin here. Then we have an advocate that we can go to named Jesus Christ (Whereby we would confess our sin so ast to be cleansed by Him).
Christ is man's Advocate with the Father. Our sin debt was paid in full by Christ. 1 John 2:1 doesn't say anything about confessing each specific sin that we commit as we commit them to Christ or else he holds back cleansing until we do.
1 John 1:8 would address both the singular sin one has committed in their life and or their many sins. In other words, lets say Joe (who is a believer) commits the sin of stealing. What if Joe refuses to admit this sin before the Lord? What if Joe (believing he is forgiven of this sin but he just doesn't feel he has to confess it or admit that it is wrong) thinks he can steal again if he wants? Would not 1 John 1:8 perfectly apply to him? For Joe is essentially saying to the Lord that he has no sin if this is the case. Joe has an erroneous seccionist view that he is forgiven of his sin of stealing regardless if he asks for forgiveness or not.
If Joe is a genuine believer then why would he refuse to admit this sin before the Lord? For Joe to continue stealing with no remorse, no repentance, no confession just bring it on is practicing sin and no one who is born of God practices sin (1 John 3:9).
1 John 1:10 is dealing with the false seccionists who believed they can sin and still be saved. They believe that they have no sin. That when they sinned in the past as a believer, they have not actually sinned.
If we say that we have not sinned, we
make Him a liar, and
His word is not in us. Does that sound like a believer to you?
The context is 1 John 1:6 and 1 John 1:7. 1 John 1:7 says if we walk in the light as he is in the light, the blood of Jesus cleanses us from all sin. How can you abide in even one unrepentant sin and say you are walking in the light as he is in the light? 1 John 1:6 says if we say we have fellowship with Him and walk in darkness (This would include just one sin), then we lie and do not the truth. This is repeated using different words in the next chapter (See 1 John 2:3-6).
You need to read verse 6 and 7 together. 1 John 1:6-7 - IF we
say that we have fellowship with Him, and
walk in darkness, we
lie and
do not practice the truth. (compare with 1 John 3:10 -
does not practice righteousness). 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. Walking in darkness is descriptive of lost unbelievers. Walking in the light is descriptive of saved believers. Only saved believers are in the light. Acts 26:18 - to open their eyes, in order to
turn them from darkness to light, and from the power of Satan to God, that they may receive
forgiveness of sins and an inheritance among those who are
sanctified by faith in Me. 2 Corinthians 6:14 - Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has
light with darkness? Ephesians 5:8 - For you were
once darkness, but now you are light in the Lord. Walk as children of lightLost unbelievers walk in darkness, not in the light. Genuine saved believers walk in the light, not in darkness. IF confirms these positions in verses 6 and 7. It's one or the other.
1 John 2:9 He who
says he is in the light, and
hates his brother, is
in darkness until now. 10 He who loves his brother abides in the light, and there is no cause for stumbling in him. 11 But he who
hates his brother is in darkness and walks in darkness, and does not know where he is going, because the darkness has blinded his eyes. Compare with 1 John 3:10. Child of God or child of the devil?