Thematic Bible: Why the law was given

Consequently, just as one offense resulted in condemnation for everyone, so one act of righteousness results in justification and life for everyone. For just as through one man's disobedience many people were made sinners, so also through one man's obedience many people will be made righteous. Now the Law crept in so that the offense would increase. But where sin increased, grace increased even more, read more.
so that, just as sin ruled by bringing death, so also grace might rule by bringing justification that results in eternal life through Jesus the Messiah, our Lord.