If you knowingly, willfully, blatantly, habitually commit sin...and you feel no remorse, no grief, no sorrow, and have no conviction about that sin...then you have NO reason whatsoever to believe that you are a Christian. You had better repent and get saved.
John is teaching this in his epistle.
I understand, but what of those who feel remorse for those human actions, yet for some reason can't remove them from their lives? It's like those traits are hardwired.