Redemption

Redemption is equated to the word ransom. Thus a redeemer is the person who pays the ransom (fine or dept or similar situation) saving them from a punishment or something else very unpleasant. In the context of Christianity Jesus is the redeemer. While we were in dept to the Law of God (by lying, stealing, blaspheming etc.), Jesus paid our fine by dying on the cross for our sins, thus redeeming us from hell.