The book of Ruth is primarily concerned with two things: land and lineage. It begins with the story of a famine and a man, Elimelech, who took his wife and sons (lineage) from the Promised Land into a foreign land in which he and his sons died, leaving Naomi without a lineage. The book of Ruth is about how Yahweh brought Naomi back to the land and provided her with a lineage through Ruth and Boaz. In chapter 1, Yahweh brings Naomi and Ruth back to the Promised Land – yet they have no inheritance there. Chapter 2 introduces the character of Boaz, a man of noble character who is willing to extend abundant favor to a poor, foreign widow. But the tension still remains, they have physical provision but they still have no inheritance in the land and no offspring to carry on their lineage. However, a hope is revealed – Boaz is their kinsman-redeemer!
In the Old Testament, a kinsman-redeemer was a close relative who could perform many functions, three of which include: redeeming the property of the deceased, redeeming (i.e. marrying) the wife of the deceased to carry on his family line, and redeeming a widow facing old age without support. This is exactly what we see Boaz do in chapters 3-4. Boaz continues showing favor and covenant faithfulness by redeeming Ruth and Naomi and fathering a son with Ruth. He himself was the instrument that Yahweh used to restore both the land and lineage to Elimelech’s family.
These themes go all the way back to the very beginning of Creation in the Garden of Eden. Adam was to be a holy representative who administered God’s holy rule over His holy lineage (people) in His holy land (place). But he failed and the world was cursed as a result. However, in the very act of cursing God promised another representative from the lineage of the woman who would wage holy war against the serpent and crush his head (Gen. 3:15).
The story of Genesis is the narrowing down of this seed through the lineage of Seth (5:1-3), Noah (5:29), Shem (9:26-27), Abraham (12:1-3), Isaac (21:12), and Jacob (25:23) until it ends with a prophecy that the rule and scepter will not depart from Judah (49:10). Yet these men did not possess the land what God promised to Abraham (Gen. 15:18-21, 17:8, Heb. 11:13-16).
The story of the Exodus and the wilderness wanderings is the story of God seeking out a holy people for Himself to worship Him in a Holy place (Exod. 3:18, 4:22–23, 5:1). The book of Joshua is the account of how the lineage of Abraham finally took possession of the Promised Land. However, Judges records the failure of the lineage of Abraham to exercise holy rule in God’s holy land and looks forward to a king from the tribe of Judah (Judges 1:1-20, 3:7-11, 17:6, 18:1, 19:1, 21:25).
This is where the book of Ruth enters into the dramatic story of redemptive history. In a little town in the hill country of Judah, an old widow returns to the land with the foreign widow of her deceased son. From that most unlikely situation, Yahweh works to restore both the land and lineage to that family – through a redeemer. Moreover, the lineage of that family is no ordinary lineage, for the foreign widow becomes the great grandmother of King David.
From the lineage of King David, God promises to provide a son who will sit on the throne in the land and rule forever (2 Sam. 7, Ps. 132:11-18). Solomon does not fulfill this promise, nor do any of the other kings from the line of David, until once again in the small town in the hill country of Judah a son is born out of extraordinary circumstances. The son is Jesus the Messiah. He is descended from Ruth and David (Matt. 1). He is the greater kinsman redeemer who reconciles His family to the Father (Rom. 8:29, Heb. 2:11-12) and provides them with an inheritance in an eternal land (Eph. 1:13-14, cf. Heb. 12:22-26, Rev. 21-22). More than that, this Christ Jesus is the redeemer who welcomes the foreigner and shows grace to the Gentile (Gal. 3:28, Eph. 2:11-22). There will come a time when we, together with Ruth, will praise the Son from her lineage in the eternal land which He has secured for us.
 You can characterize these two themes many different ways: geography and genealogy, place and people, dominion and dynasty, etc.