The Greek word for redemption actually refers to slaves who were purchased in a marketplace. 
In a spiritual sense, all of us were slaves to sin until Jesus purchased us out of the slave market and set us free from sin’s bondage.

Let me give you a picture of what Jesus’ death on the cross did to purchase our freedom. Imagine you’re in a busy marketplace with a lot of commerce going on. In the center of the marketplace, you’re in the middle of an auction, where you are being bid on. As each successive bid is shouted out, you look in the eyes of those who are bidding on you and try to size them up. Are they kind or cruel?

Just as the auction is winding down, a stranger from the crowd stands up and offers a bid a thousand times higher than anyone else’s bid. There is no way anyone could ever match or beat that bid. As the auctioneer hastily accepts it, you look into that stranger’s eyes and realize he isn’t bidding on you to use you, like a slave. He’s buying you in order to set you free. That’s just what Jesus did for you. Saved by the Son – Bought for a price (Jesus on the Cross) He paid the price to set you free. The price for your freedom was so high you could never pay it. But he paid it for you.