Ontological, Moral or Forensic?

Last week I led children's work on Mark 7 (see previous post) and in the light of vv21-23 described the human heart as a "mudspring" - for out of it flows all that makes us unclean. Any solution we could dream up would only keep it clean for a second or two, as we're always creating new mud/sin.
Our minister has four children, of whom three were in that class, and the message got through. So in today's family service, he picked up on the language to present Jesus as the one who makes us clean from Mark 7:24-end.
It got me thinking about a category mistake.
What is sin? And what is uncleanness?
Sin is something we not merely do - it has to do with what we are. Sin flows out of our hearts and it is fundamental to understanding our place in the universe. As something that flows out of our hearts, it has ontological value - it has to do with the ousia anthropou, the being of man. But as fundamental to our place in the universe, a place defined by our status vis-a-vis God, it has moral and forensic value, being essentially about our standing before a holy God and our guilt before a judging God. Sin is therefore a complex category.
Unclean is not. Therein lies my category mistake.
I foolishly so equated mud with sin that I gave the impression that God is essentially someone who can't stand hoovering so doesn't let any dirt in the house. Which is understandable - I sometimes do have attacks of "I must get this place clean". But unclean is not like that. It is a status declared by the priest over persons, food, buildings and other items as representative of a holy and judging God.
So we don't need a good scrub. We need a change of status. We don't need washing through, as ultimately Catholic theology implies. We need a change of status, as Luther and Calvin taught. We need someone to cause our status to be holy, done in the Old Testament by sacrifice; we need someone to give us a right standing before God, a work that can only be done by a good defence lawyer and someone to pay the fine. Now read 1 John 1:5-2:2.