This room is the heart of that man who knows not the grace of God.  The dust is his first sin and the vice that is in him.  He that swept first is the Law, but she who made the floor moist is The Book which tells Good News to Man.  Now as soon as you saw the first of these sweep, the dust did so fly that the room could not be made clean by him; this is to show you that the law as it works does not cleanse the heart from sin, but gives strength to sin, so as to rouse it up in the soul.  
Then you next saw the maid come in to lay the dust; so is sin made clean and laid low by faith in The Book.

-John Bunyan
Pilgrim's Progress

*The girls and I have started reading this book recently.  I'm not sure how much they understand….or even how much I understand!  But there are these word pictures scattered throughout that illustrate truth so perfectly.