From this week's interim Bible study at the West Virginia state capitol:
Paul understood the “Great Exchange” that takes place in gospel accounting. When we repent and place our faith in Christ, God places all of our sin on Jesus’ account as He is punished in our place and on our behalf. The goodness, or righteousness, of Christ’s perfect life is then placed on our account. What a glorious transaction of God’s grace! No wonder Paul counted all earthly things as loss in view of knowing Christ.
You can read or download the complete study, "Gospel Accounting in the Capitol", here.