We Christians use a lot of "insider" terminology.  One of the words we frequently use is the word redeem. We say that we are "redeemed" by Christ, or that God is our Redeemer.  

Whatever does that mean? Usually in today's world, the only time we see the word redeem outside of a Bible study is on a coupon! For example, "Redeem this voucher for one free Chik fil A sandwich!"