"habitual (1Jn 3:6, with the Greek present tense). "
Giver, Pax hit the nail on the head. Each of the texts you are quoting has to do with habitual sinning.
I John 1:5-2:2
This is the message we have heard from him and declare to you: God is light; in him there is no darkness at all. If we claim to have fellowship with him yet walk in the darkness, we lie and do not live by the truth. But 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, purifies us from all sin. ** If we claim to be without sin, we deceive ourselves and the truth is not in us. If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.** If we claim we have not sinned, we make him out to be a liar and his word has no place in our lives. My dear children, I write this to you so that you will not sin. But if anybody does sin, we have one who speaks to the Father in our defense—Jesus Christ, the Righteous One. He is the atoning sacrifice for our sins, and not only for ours but also for[a] the sins of the whole world.
Giver, what you need ot look up is “sin unto physical death”
1 Corinthians 5:5 To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
1 John 5:15-17
15And if we know that he hears us—whatever we ask—we know that we have what we asked of him. 16If anyone sees his brother commit a sin that does not lead to death, he should pray and God will give him life. I refer to those whose sin does not lead to death. There is a sin that leads to death. I am not saying that he should pray about that. 17All wrongdoing is sin, and there is sin that does not lead to death.