Why write Ruth?

Bethany and I have been going through the book of Ruth for about a month together (reading a chapter once or twice a week).  Since the book is a simple, beautiful narrative about a family in Moab and Israel, what is God's purpose for it in the Scriptures? We tried thinking through this from a practical perspective rather than simply a theological one. Here are five significant and relatively unique contributions that we feel Ruth makes to our understanding of God, His character, and how that is to be displayed in us, His people.

1.  After the books of the Law, the conquest of Canaan, and the self-degrading of Israel during the times of the judges, it throws a spotlight on a 'pagan' outsider's humble faith.

2.  It honors righteous women. Few books of the Bible focus completely on a single life, and none are so intimate in their portrayal of a godly family. This is a book about simple, family righteousness, highlighted in a woman's beauty.

3.  In Boaz, it has a living presentation of a God-fearing, Law-honoring life even during the dark times of the judges.

4.  As well, it provides a picture of a redeemer whose actions often mirror The Redeemer's.

5.  It shows God's plan for David by starting David's line long before Saul was king, during the time of the judges.  (It seems to me from other passages that David would have been God's chosen king whether or not Israel had insisted on a king 40 years before.)