What does the word redemption mean?

Les explains that redemption is the process of buying us back. He notes that we are justified freely, without a cause, by His grace, but grace supplied the redemption that is in Christ Jesus. He contrasts this with trying to earn salvation through rigmaroles—dotting I's, crossing T's, walking an aisle, shaking a preacher's or deacon's hand—and thinking we have done all that is required. That approach, he says, leaves no faith in the Gospel, and Christ becomes of no effect to those justified by the law, legalism, or works. He then returns to Romans 3, where all have sinned and come short of the glory of God, and being justified freely by His grace through the redemption in Christ Jesus.