9 No one who is born of God will continue to sin, because God’s seed remains in them; they cannot go on sinning, because they have been born of God.

Jesus remained without sin, he was born of God. No other man thus far has remained without sin, otherwise they could have been the lamb sacrificed having no spot or blemish. We are told that Jesus was perfect, no other man is called perfect, righteous of course but not perfect. Paul speaks of people not yet receiving the promise of being made perfect, as they will all receive it together. There is NO THEORY, there is the simplicity of knowing more than one scripture and having the capacity to think of those scriptures all at the same time.