The word redeem had legal meaning in the Hebrew days of the Old Testament:
The term meant to buy back a person, property or right to which one had a previous claim through family relation or possession. The term is found 18 times in the Old Testament. Someone who had to sell himself into slavery because of poverty, for instance, could have his freedom bought back by someone called a redeemer, usually his next of kin.
In the Book of Ruth, we read that Boaz redeemed the widow Ruth in this manner when he bought back the land that belonged to Ruth’s mother-in-law, Naomi, now also a widow. As the “redeemer” in this case Boaz said, “You are witnesses this day that I have bought from the hand of Naomi all that belonged to Elimelech and all that belonged to Chilion and to Mahlon. Also Ruth the Moabite, the widow of Mahlon, I have bought to be my wife, to perpetuate the name of the dead in his inheritance, that the name of the dead may not be cut off from among his brothers and from the gate of his native place. You are witnesses this day” (Ruth 4:9-10).
This is a beautiful foreshadowing of how Christ redeemed the Church and bought it back as his Bride. He saw us in our lost state and made sure we had a family, a home and a relationship with him.
This is why the word redeem is so powerful in Scripture. It means reconnection to the family of God that was lost because of our sin. And the payment for this redemption? The body and blood of Jesus. He gave completely of himself that he might give us an inheritance with him forevermore. What a glorious transaction!