by His grace: God places us in a right relationship with him, not because he must, but because God chooses to give us his favor through Christ Jesus. Because we are helpless slaves of sin (3:9), our righteous status before God can never be earned (see 4:4–5).
through the redemption that is in Christ Jesus: In Paul’s day, redemption referred to the price paid to free a slave. God paid our redemption price with the blood of his own Son to rescue us from our slavery to sin (see 3:9). TThis language was used in the Old Testament to refer to the exodus from Egypt, the first redemption of God's people from slavery (see 2 Samuel 7:23). God promised that he would again redeem his people (Hosea 13:14; Micah 4:10).