The word redemption was used in the Biblical world to denote
the act of buying a slave out of bondage
in order to set him free.
The Bible teaches that in our natural state, as unbelievers, we
are slaves to sin:
John
Romans
But Jesus Christ redeemed us (i.e. paid the price to set us free) from our bondage to
sin with His own blood!
Galatians 3:13 - Christ redeemed us from the curse of the law by becoming
a curse for us, for it is written: "Cursed is everyone who is hung on a
tree.
Titus 2:13b-14 - Jesus Christ . . . gave Himself for us to
redeem us from all wickedness
Ephesians 1:7 - In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of
God's grace