You only show your ignorance when you make the claim that everyone being addressed is a believer. "All that be in Rome". That means anyone who hears the letter being read.
Romans 1:7 To all that be in Rome, beloved of God, called to be saints: Grace to you and peace from God our Father, and the Lord Jesus Christ.
Of course you just leave out what Paul says here:
"To all that be in Rome, beloved of God, called to be saints: Grace to you and peace from God our Father, and the Lord Jesus Christ. First, I thank my God through Jesus Christ for you all, that your faith is spoken of throughout the whole world" (Ro.1:7-8).
Of course you only quoted verse seven because verse eight proves that the epistle is only addressed to believers. You wouldn't want anyone to see that, would you?
Those "believers who walk in darkness" like you claim in 1 John 1?
You haven't yet learned about English pronouns yet. Here are John's own words about that:
"And these things write we unto you, that your joy may be full. This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all. If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth: But 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" (1 Jn.1:4-7).
It is evident that the first two instances where John uses the pronoun "we" the reference is to believers. And there is nothing that even hints that the meaning of "we" in the next two usages has changed its meaning.
But according to you these two instances where John uses the pronoun "we" no longer is referring to believers but now it refers to unbelievers.
That is just one example how you mangle the Scriptures in order to make them fit your preconceived ideas. And then you have the audacity to claim that Peter was not walking in darkness here:
"But when Peter was come to Antioch, I withstood him to the face, because he was to be blamed. For before that certain came from James, he did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them which were of the circumcision. And the other Jews dissembled likewise with him; insomuch that Barnabas also was carried away with their dissimulation. But when I saw that they walked not uprightly according to the truth of the gospel, I said unto Peter before them all, If thou, being a Jew, livest after the manner of Gentiles, and not as do the Jews, why compellest thou the Gentiles to live as do the Jews?" (Gal.2:11-14).
Even though Paul says that Peter was to be blamed and that Peter walked not uprightly according to the truth of the gospel you say that He was not walking in darkness but instead He was walking in the light.
You prove that you will say anything, no matter how ridiculous, to win an argument.
Who is Paul addressing here when he says, "O man"?
Romans 2:3 And thinkest thou this, O man, that judgest them which do such things, and doest the same, that thou shalt escape the judgment of God?
It is speaking of the human race in general and the fact that they are under judgment. He continues until he sums up His argument where he speaks of the judgment of man according to his deeds or works:
"But after thy hardness and impenitent heart treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God; Who will render to every man according to his deeds: To them who by patient continuance in well doing seek for glory and honour and immortality, eternal life: But unto them that are contentious, and do not obey the truth, but obey unrighteousness, indignation and wrath, Tribulation and anguish, upon every soul of man that doeth evil, of the Jew first, and also of the Gentile" (Ro.2:5-9).
By using these words Paul is leading up to this conclusion that no one is saved by his works. Paul is not addressing anyone in particular in these verses but instead mankind as a whole.