The Old Testament book of Ruth is named after the great-grandmother of David, and an ancestress of Jesus (Matthew 1:1, Matthew 1:5). Note that there are two books in the Bible, Ruth and Esther, which are named after women.
The book of Ruth is set in the time of the judges, a period of religious and moral degeneracy, national disunity and general foreign oppression, though it reflects a temporary time of peace between Israel and Moab. It gives a series of intimate glimpses into the private lives of the members of an Israelite family, and also presents a delightful account of the remnant of true faith and piety in the period of the judges.
The author focuses on Ruth’s selfless, unswerving devotion to Naomi (Ruth 1:16-17, Ruth 2:11-12, Ruth 3:10, Ruth 4:15) as well as on Boaz’s kindness to these two widows. They are striking examples of lives that embody in their daily affairs the self-giving love that fulfills God’s law (Leviticus 19:18, Romans 13:10).
Ruth, who is a young woman of Moab, shows complete loyalty to the Israelite family into which she has been received by marriage. That and her total devotion to her desolate mother-in-law mark her as a true daughter of Israel and a worthy ancestress of David. She strikingly exemplifies the truth that participation in the coming kingdom of God is decided, not by blood and birth, but by the conformity of one’s life to the will of God through the “obedience that comes through faith” (Romans 1:5). Her place in the ancestry of David signifies that all nations will be represented in the kingdom of David’s greater Son. In Jesus, the great “son of David” (Matthew 1:1) and His redemptive work, the promised blessings of the kingdom of God find their fulfillment.
Redemption is a key concept throughout the book of Ruth and its Hebrew variants occur 23 times. The book is primarily a story of Naomi’s transformation from despair to happiness through the selfless, God-blessed acts of Ruth and Boaz.
The book of Ruth is a Hebrew short story (only 4 chapters long) told with consummate skill. Among historical narratives in Scripture, it is unexcelled in its compactness, vividness, warmth, beauty and dramatic effectiveness---an exquisitely wrought jewel of Hebrew narrative art.
(Summarized from parts of the NIV Introduction to the book of Ruth)
(I created the image above in Adobe Illustrator to use as an image with this blog post)