so that as sin reigned in death, grace too might reign through righteousness, leading to eternal life through Jesus Christ our Lord.
In context
19As by one man’s disobedience the many were made sinners, so by the obedience of one the many will be made righteous. 20The law slipped in so that the trespass would grow; but where sin grew, grace overflowed beyond all measure, 21so that as sin reigned in death, grace too might reign through righteousness, leading to eternal life through Jesus Christ our Lord.