NO! Every epistle is written to ChristIans.
Look at chapter 2 verse 1..
My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous:
He calls them “my little children”. These are not alien sinners. Non Christians.
look at verse 12..
I write unto you, little children, because your sins are forgiven you for his name's sake.
He is writing to people whose sins have been forgiven. These are not people who are not “born again”.
There was not any epistle that was written to non Christians.
Yeah not all the verses are addressing Christians. For example Romans 10:9-10 does not seem like that is talking to the Christian. A lot of the Bible is this way.
I see this 1 John chapter 1 and 2 as we are either walking in our old dead nature if we are into sin. Or we are walking in the spirit if we are not into sin.
Chapter 1
6 "If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:"
6. Not in him because we are either not saved or have not put on the new man.
7 "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."
7. In him because we are saved and have put on the new man.
8 "If we say that we have no sin, we deceive ourselves, and the truth is not in us."
8. Not in him because we are either not saved or have not put on the new man.
9 "If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness."
9. In him because we are saved and have put on the new man.
10 "If we say that we have not sinned, we make him a liar, and his word is not in us."
10. Not in him because we are either not saved or have not put on the new man.
Chapter 2
1 "My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous:"
1. Not in him because we are either not saved or have not put on the new man.
2 "And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world."
2. Not in him because we are either not saved or have not put on the new man.
3 "And hereby we do know that we know him, if we keep his commandments."
3. In him because we are saved and have put on the new man.
4 "He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him."
4. Not in him because we are either not saved or have not put on the new man.
5 "But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him."
5. In him because we are saved and have put on the new man.
6 "He that saith he abideth in him ought himself also so to walk, even as he walked."
6. In him because we are saved and have put on the new man.