And while it started off good, our human ancestors did mess up quite a bit.
But, remember, "In Christ, there is a new creation."
Paul goes on to tell them--and through them, us--what our assigned task in this new creation is to be. We are ambassadors for Christ. Ambassadors--we travel, reach out, communicate. God's appeal is made through us--in our travel, reaching out, and communicating, we are charged with transmission of what God wants them to know.
Paul had explained the meaning to the Corinthians, and now they were to live it out so others would also know it.
Since the first creations, humans had given in to sin. Now, it's time to defeat it.
For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.
Note: We are not being called to be self-righteous but rather to be part of and communicators of God's righteousness.